DEVICE FOR DETERMINING CHEMICAL SUBSTANCES IN ANALYZED MEDIUM

DEVICE FOR DETERMINING CHEMICAL SUBSTANCES IN

ANALYZED MEDIUM

The present invention in general relates to semiconductor devices. In particular, the present invention relates to semiconductor diode sources of and infrared radiation receivers operating in the middle infrared region 1.6-5.0 mcm, and also devices for determination of chemical substances in analyzed medium, containing such diode sources and receivers of infrared radiation. Proposed device can be used for determining the presence of and/or content of chemical substances, for example such as methane, carbon dioxide and others.

For analysis of composition of much component gas mixtures employed method of infrared spectroscopy. Presence of narrow selective absorption strips different intensity of in the middle infrared spectrum, characteristic for each analyzed component, allows select optimal conditions for measuring concentration of water vapor, methane, carbon oxide and dioxide and others.

At the present time a wide propagation of proposed device gas analysis based on sources and photodetectors of infrared radiation. While for achieving high-efficiency specified devices gas analysis is necessary, necessary, to parameters of its composite parts were synchronized spectral characteristics, quickly effect of, temperature characteristics. Besides, sources of infrared radiation, used in devices gas analysis should possess sufficiently narrow radiation directivity. Not less than an important is selection of photodetector, which should possess not only high efficiency converting incident on it radiation, but and required spectral distribution photosensitivity and quickly effect.

Known semiconductor source of infrared radiation (patent ukraine on invention № 85645, MPK H01L 33/00, publ. 10 february 2009), chosen as prototype, which has semiconductor chip, heat-conducting base with recess, side surface of which reflects radiation chip and has shape cut cone, and also optical coating from transparent for radiation material. Emitting chips are made based on solid solutions AZV5 and emitted in the middle infrared spectrum on wave lengths 2.5-5.0 mcm. For manufacturing optical coating were used semiconductor khalkogenidnye glass systems as-s-se, as-sb-s-se, ge-sb-s, ge-bi-s, components of which are taken in corresponding proportions with provision of preset value of refractive index. Refraction index chalcogenide glass on wave length 1=4,0 mcm, depending on composition of components, No from 2.0 to 2.7. The thickness of the base optical coating exceeds height of its elongated hemisphere not less than two times.

However khalkogenidnye glass specified systems are very refractory and have high temperature point, that limits their use from the point of view of overheating diode heterostructures, leading to significant deterioration of their characteristics, and bad wettability limits their use from the point of view of types of used bodies, in particular, khalkogenidnye glass specified systems not may be used with flat bodies.

From level of technology is known method of applying optical coating based on much component chalcogenide glass (UA33848, G01D5 /26, publ. 10 JULY 2008). According to known method ground pieces of chalcogenide glass is filled in quartz reactor, is set temperature, which not less than 100K exceeds softening temperature chalcogenide glass corresponding chemical composition. Simultaneously heated active element to temperature, which approximately 10 deg to lower than solder melting temperature of electric contacts to active element, thereby preset shape and good adhesion optical coating to active element. For chalcogenide glassy alloys of system pb-ge-se the temperature of the heater is 650K, and for glass of system ge-ga-se temperature is 570K. in the process of passage of quartz reactor through thermal zone of heater, available in it of pieces of chalcogenide glass soften. Under the action of gravity through the lower hole of reactor drop falls on active element. Furthermore, under action of surface tension forces and viscosity of chalcogenide glass and adhesive capacity wetting active element optical coating acquires radially symmetrical form. To displacement of drops of chalcogenide glass at its contact with surface active element formation of volumetric optical coating without air interlayers between glass and crystal and without disturbance of electric contacts. By completion of process quartz reactor is moved vertically upward beyond the zone of action of heaters, and active element with applied optical coating is moved horizontally behind limit action of heater, where its cooling to room temperature.

However khalkogenidnye glass, used in known method of applying optical coating, have high temperature point, consequently, application on semiconductor chip glass, heated to such a temperature, very negatively alter on structure p-n junction of this semiconductor chip.

Besides, at usage of the known method is required take additional measure for providing of precision of centering holes of reactor relative to semiconductor chip for providing optical coating symmetric relative to its longitudinal axis.

Is known also infrared gas sensor for determining the most common contaminating atmospheric gases, such as with, S0_2,SN4, no (ua 90194, publ. 12 APRIL 2010). Known device has working dish, with input and output channel for analyzed medium and parabolic mirror. Besides, device has two identical of the infrared radiation source and receiver of infrared radiation with optical filter, which are located on one side of the working dish. Sources of infrared radiation contain optical coating, made from chalcogenide glass systems ge (pb)-sb (bi, ga)-s (se).

However known device has considerable dimensions, as its diameter is determined location in one flat sti of base two, sources of infrared radiation and one receiver of infrared radiation, each of which is located in a separate housing. Besides required use of additional of optical filters, and also parabolic mirrors.

From level of technology is known gas analyser (US2001048079, G01N21 /35, publ. 06 december 2001), chosen as prototype, which contains substantially cylindrical hollow body, having inlet and outlet channels for analyzed gas. On the housing inner surface is applied metal coating, made with possibility of reflection of infrared radiation. Besides, gas analyser contains infrared radiation source and infrared radiation receiver, located on the opposite ends of the body on one optical axis. In quality of sources of infrared radiation used nedispersionnye sources of infrared radiation (NDIR). Data radiation sources have wide spectral strip, consequently, for isolating required spectral range for determining specific chemical substance is required to use corresponding optic filters. Besides, similar radiation sources expose to heavy heating, which can reduce accuracy of performed measurements, and also have large power consumption.

-Miniature device for determining chemical substances in analyzed medium, has high sensitivity, accuracy of measurements and low consumption of electric power.

According to the present invention a semiconductor diode for middle infrared spectrum range, containing at least one semiconductor chip, made on the basis of heterostructure, having current-conducting contacts and placed on heat-conducting base, and also optical coating from material based on complex semiconductor of chalcogenide system, containing as, s, se, at that khalkogenidnaya system contains additionally at least one halogen, selected from the group, containing i, br, ci.

Technical result, achieved by the offered invention, consists in Your Aras temperature of material fluidity optical coating. Owing to this reduced action of high temperatures on semiconductor chips in the process of production of the sources and receivers of of infrared radiation, and, consequently, reduced probability appearance of defects p-n junctions under action of high temperatures.

Besides, -diffusion Aras quality of created by optical coating. This diffusion lu quality of is achieved due to the fact, that glass with mentioned composition has low crystallization capability, is homogeneous on the structure, provides for high quality drops of without bubbles and no cords.

Heterostructure can represent structure gasb/ GalnAsSb / AIGaAsSb /gasb, inas/ lnAsSb / lnSbP or inas/ lnSbP / lnAsSbP.

According to one more aspect of the invention, a method of forming optical coating of semiconductor diode for middle infrared spectrum range, according to which is a material based on of complex semiconductor chalcogenide systems, is heated this material to temperature of material fluidity and applied heated material on semiconductor chip, after that cooling of produced optical coating, said material represents complex semiconductor khalkogenidnuyu system, containing as, s, se and at least one halogen, selected from group i, br, ci.

According to one version of realization of the present invention application of heated material may be drop-by-drop. In this case the mentioned material is taken in the amount, exceeding amount of material, required for forming optical coating, and after applying the indicated material on semiconductor chip its turned with provision of dripping of excessive amount of material and forming optical coating radially symmetrical shape.

According to one version of realization of the present invention before application of material is semiconductor diode in position, at which its surface, on which is semiconductor chip, faces downwards, and applying material is contact the surface of semiconductor diode with surface of material with provision of wetting this surface of semiconductor diode material, then it is withdrawn semiconductor diode and provide drain excessive amount of material with formation of optical coating, having radially symmetrical form.

According to still one version of method implementation, is filled with material shape, provided with recess, configuration of which corresponds to the required configuration of optical coating, placed semiconductor diode in position, at which its surface, on which is semiconductor chip, faces downwards, and Be material is by bringing into contact the surface of semiconductor diode with surface of material in said recess, at that cooling optical coating is carried out in said form, after which the semiconductor diode is removed.

According to one more aspect of the invention, the device for determining chemical substances in analyzed medium, containing tubular body, in which there are inlet and outlet channels for analyzed medium, at least one infrared radiation source, installed on one end of the body, and at least one receiver of infrared radiation, mounted on body other end, source of infrared radiation and infrared radiation receiver are located on one optical axis, which coincides with the longitudinal axis of the tubular body, and spectral are coordinated with each other, source of infrared radiation and infrared radiation receiver are made on the basis of semiconductor diode for middle infrared spectrum range, containing at least one semiconductor chip, made on the basis of heterostructure, having current-conducting contacts and placed on heat-conducting base, and also optical coating from material based on complex semiconductor of chalcogenide system, containing as, s, se and at least one halogen, selected from the group, containing i, br, ci.

In the device body may be additionally mounted light-reflecting tube.

Besides, device can additionally contain at least one conical reflector, located on source of infrared radiation or receiver of infrared radiation. In other case device can additionally contain two conical of reflector, one of which is on the source of infrared radiation, and the other is located on receiver of infrared radiation.

Device also may additionally contain support radiation receiver.

Other aspects of the present invention may be understood from subsequent description of preferable embodiments of realization and drawings.

Further is put detailed description of possible Embodiment of the Invention with links to drawings, on which:

on Figure 1 is shown the type of side in section of semiconductor diode for middle infrared spectrum range according to the present invention;

on Figure 2 is shown the type of side in section of semiconductor diode for middle infrared spectrum range one version according to the present invention;

on Figure 3 is shown the type of side in section of semiconductor diode for middle infrared spectrum range one version according to the present invention;

on Figure 4 is shown the type of side in section of semiconductor diode for middle infrared spectrum range one version according to the present invention;

on Figure 5 is shown the type of side in section of device for determination of chemical substances in analyzed medium according to the present invention;

on Figure 6 is shown the type of side in section of the proposed device for determination of chemical substances in analyzed medium one version according to the present invention, equipped with conical reflectors;

on Figure 7 is shown the type of side in section of the device, shown on Figure 6, additionally containing support radiation receiver;

on Figure 8 schematic cradle depicted installation for applying optical coating according to one version of realization of the method of application of optical coating on semiconductor diode;

on Figure 9 schematic cradle depicted sequence of forming optical coating in installation, indicated on Figure 8, after turning semiconductor diode.

As shown on figs. 1-4, proposed semiconductor diode for middle infrared range spectrum has a teploprovodnoe base 1, semiconductor chip 2, located on specified base, and optical coating 3. Optical coating 3 is manufactured from material based on of complex semiconductor chalcogenide glass of system as-s-se, which additionally contains at least one halogen, selected from the group, containing i, br, ci. May be also used system sb-s-se, containing at least one halogen, selected from said group.

According to drawn testing required characteristics chalcogenide glass can be obtained at content as in amount 5-50% from total volume, s in amount 10-50% from total volume, se in amount 30-70% from total volume. Amount of at least one halogen, chosen from group, containing i, in, ci should be up to 20% of total volume of. In case of simultaneous use of two or three of said halogens their total amount also should be up to 20% of total volume of.

Addition of in composition of chalcogenide glass at least one of the specified halogens, for example i, allows to achieve glass transition temperature of about 35° with and temperature point to 140-160° with. At that variation of concentrations of elements of system, and also amount of used halogens, allows to change glass transition temperature in wide range of temperatures. Such Your lu temperatures glass transition point and point makes application glass or encapsulation of more effective the production, less exacting to equipment for heating composition. Besides, decreases percent of rejects of finished products due to Your condensate influence of thermal impact on semiconductor structure and its electric contacts, that allows to expand range of application glass for more sensitive to thermal impact of semiconductor materials. Besides, glass with mentioned composition has low crystallization capability, is homogeneous on the structure, provides for high quality drops of without bubbles and no cords.

Application of optical coating from chalcogenide glass allows narrowing of quiescent pattern approximately up to 30° and increased external quantum yield to 6 times.

Glass presented systems as (sb)-s-se-l (br, ci) may be used as antireflection coating of semiconductor diodes for middle infrared spectrum range, operating in spectral range 1.6-5.0 mcm. It is transparent in spectral range 0.73-10 mcm, and refraction index is 2.4 on wave length 0.8 mcm.

Teploprovodnoe base 1 can be represented standard housings then -18, then -5, then -8 and then -39, which differ diameter and number of leads, and also SMD housings for surface mounting with diameters 3 or 5 mm.

The proposed design of the diode can be used for a light-emitting diodes, and photodiodes. As semiconductor chip 2 is used respectively light diode chip or a photodiode chip.

For manufacturing of the light emitting diode according to the present invention can be used emitting plate with wavelength of radiation maximum in spectral range 1.8-2.4 mcm, based on heterostructure, including successively arranged substrate, containing gasb, buffer layer, containing solid solution GalnAsSb, active layer, containing solid solution GalnAsSb, limiting layer, containing solid solution AIGaAsSb, and contact layer gasb. Manufacturing technology given heterostructure described in Eurasian A № 018300 "heterostructure based on solid solution of GalnAsSb, method for the production thereof and light diode based on this heterostructure" the present complainant.

In manufacturing process of the light emitting diode plate divided into separate chips, which are mounted on standard body for optoelectronics type then -18, then -39, then -8, SMD (figs. 1-3). Further is made razvarku or raspaiku electric contacts. After that is applied on obtained light emitting diode chalcogenide glass, for example of system as-s-se-i.

If necessary creating electric insulation chip from body can be used silicon or ceramic substrate of 4 (Figure 3).

Besides, for manufacturing light-emitting diode according to the present invention can be used emitting plate with wavelength of radiation maximum in spectral range 2.6-3.1 mcm, based on heterostructure, including successively arranged substrate, containing inas, barrier layer, containing InSbP, active layer, containing InAsSbP. Manufacturing technology given heterostructure described in Eurasian A №018435"method of manufacturing heterostructures (versions) for middle infrared-range, heterostructure (versions) and light diode and photodiode based on this heterostructure" the present complainant.

Types of used bodies and system of chalcogenide glass are similar to used in the previous version of the light emitting diode.

For manufacturing the photodiode according to the present invention can be used fotodiodnaya plate with wavelength of radiation maximum in spectral range of 3.1 -4.7 mcm, based on heterostructure, containing serially located substrate, containing inas, active layer, containing InAsSb, and barrier layer, containing InSbP. Technology of manufacture of said heterostructure described in Eurasian A №018435"method of manufacturing heterostructures (versions) for middle infrared-range, heterostructure (versions) and light diode and photodiode based on this heterostructure" the present complainant.

Types of used bodies and systems chalcogenide glass are similar to used in the previous version of the photodiode.

In another version of the photodiode is used a photodiode plate with red boundary of photosensitivity 2.4 -2.5 mcm, based on heterostructure, technology of manufacture of which described in Eurasian A № 018300 "heterostructure based on solid solution of GalnAsSb, method for the production thereof and light diode based on this heterostructure" the present complainant. Said heterostructure has serially arranged substrate, containing gasb, active layer, containing GalnAsSb, layers of electric and optical limiting, containing AIGaAsSb, and contact layer, containing gasb. Further via photolithography is formed fotodiodnye chips with diameter light-sensitive platform 0.2; 0.5 ; 1 and 2 mm. Further plate are separated on separate chips, is mounting on housing and their pouring khalkogenidnym glass. Types of used bodies and systems chalcogenide glass are similar to used in the previous version of the photodiode.

Version of the proposed device for determining chemical substances in analyzed medium shown on Figure 5. Device has tubular body 5, equipped with inlet and outlet channels 6 for analyzed medium. Device also contains at least one source of 7 of infrared radiation, located on one end of the body 5, and at least one receiver 8 of infrared radiation, located on opposite end of casing 5. Indicated source of 7 and receiver 8 glued into rim 9 and 10, respectively, which, in its turn, are installed in the body 5 on opposite ends. Said source of 7 and receiver 8 of infrared radiation are on one optical axis, coinciding with housing axis 5.

Source 7 and receiver 8 of infrared radiation are made as described above with links to figs. 1-4. Source 7 and receiver 8 of infrared radiation is selected in such a way, that they spectral are coordinated with each other. In particular, if infrared radiation source operates in range 1.8-2.4 mcm, then the receiver of infrared radiation should have red boundary of 2.4-2.5 mcm. If same source emits at 2.8-3.6 mcm, then the receiver should have red boundary of 3.6 mcm and T. d.

If necessary in proposed device can be made more than one of the infrared radiation source and more than one receiver of infrared radiation (not shown).

Besides, in the body can be installed light-reflecting tube 11, located coaxially with it. Light-reflecting tube 11 may have substantially cylindrical shape, and its length can reach 20 cm and more. At that diameter of tube remains practically constant and can be 2 to 9 mm.

For provision of high reflecting capacity of inner surface of the tube 11 it can be made from stainless steel with electric polishing and have reflection coefficient inner surface of not below 90%. Besides, can be made metallisation inner surface of the tube 1 1.

Besides, device may be additionally equipped with at least one conical reflector 12, mounted on the side of the source 7 of infrared radiation or receiver 8 of infrared radiation. One version, shown on Figure 6, device may have two conical of reflector, one of which is located on the side of the source 7, and the other on the side of receiver 8.

Conical reflector is made from material, having high reflection coefficient, in particular can be used duraluminium or stainless steel, which allows to reduce loss of radiation.

Use of conical of reflector allows additionally narrowing of radiation pattern of source and/or receiver of infrared radiation.

On Figure 7 shown one more version of the device, which differs from the versions, depicted on Figure 6, the presence of additional reference receiver 13 radiation, located, for example, in body conical of reflector. As reference radiation receiver is preferably photodiode. Support radiation receiver preferably is placed as close as possible to source of infrared radiation, it must be located between source of infrared radiation and channel 6 for gas, the nearest to this source of infrared radiation. Since measurements are performed in atmosphere of the gas under study, then part of radiation is absorbed. Therefore, the less is optical route, the smaller will be absorption. Consequently, for producing information about initial ( nepogloshchennom ) radiation from source of infrared radiation, reference receiver should is closer to this source of radiation. Actual placement of reference radiation receiver is limited by the structural features of the system, in other words size of chips, type of used bodies and electric branching contacts. On Figure 7 dotted lines also conditionally shown stroke of beams in device with installed support radiation receiver.

Device according to one of the presented variants of realization operates as follows. Power source 7 of infrared radiation and synchronisation of its operation with operation of synchronous detector effected from pulse source of current. At feeding current on source 7, it begins to radiate. Specified radiation collected in the beam with means of optical coating. Besides, beam of radiation may be additionally narrowed with the aid of conical of reflector. Further radiation passes through body 5 in direction of receiver 8 of infrared radiation. In case of use in device design reference receiver 13 of infrared radiation, part of the said radiation is fed on this reference receiver 13. At feeding into classification device of analyzed medium is partial absorption indicated radiation tested chemical substance. Further radiation goes on receiver 8 of infrared radiation.

Current, obtained from receiver 8 of infrared radiation, is transformed to voltage, then successively is made amplification of signal by means of preamplifier and straightening it by means of synchronous detector. After that signal arrives at registering device, made with possibility of mathematical processing of signal, for example a computer. Are comparison processed signal with the reference value, measured in conditions of pure atmosphere and planted in mathematical processing of signal.

In case if additionally is used support radiation receiver, ratio of signals reference receiver and measuring receiver allows to make output of concentration of chemical substance.

According to one more aspect of this invention method of making optical coating of semiconductor diode for middle infrared spectrum range, which consists in the following. Is a material based on complex semiconductor of chalcogenide system, containing as, s, se and at least one halogen, selected from the group, containing i, br, ci. Said material is taken in the amount, exceeding amount of material, required for forming optical coating, then heated this material to temperature of material fluidity and applied heated material on semiconductor chip after that cooling of produced optical coating.

According to one version of realization of the method of application of optical coating, application of is made drop-by-drop, and after applying the indicated material on semiconductor chip is turned its with provision of dripping of excessive amount of material. With the amount of excessive material is determined from equilibrium of gravity force, acting on drop, and adhesion force material to chip.

Proposed method of manufacturing optical coating of semiconductor diode can be implemented by means of installation, indicated on Figure 8. This plant has heat cabinet 14 from glass door, inside of which on rails 15 is located platform 16, intended for fastening of semiconductor diodes 17. To platform is connected manipulator 18, allowing to motion of platform to the right and to the left, as shown arrow and, and also coup platform on 180° inside the furnace. Due to use of like of manipulator placement of batch of semiconductor diodes on platform and sequential application of glass on them may be without reboot furnace, that allows to reduce considerably time production expenses of semiconductor diodes.

In upper part of cabinet is placed quartz reactor 19, which is preliminarily is filled with easily fusible khalkogenidnym glass 20 according to the present invention.

To reactor is batcher 21, is made with possibility of creating pressure command. Batcher preferably is made with possibility of checking value of pressure, by means of handle 22, time of supply of pressure by means of handle 23, and also value back pressure by means of handle 24. The latter adjustment prevents unsanctioned ingress of glass on platform. As such batcher can be used represented on the market batcher DSPE501 a-lf of firm Fisnar. Said batcher allows precision control of mass drops of. To tank 21 are connected receiver and pump 25.

Advantage of this system is its tightness, which allows to exclude ingress of dirt, dust and others. in glass, and other side of harmful vapors into human organism. For creating pure atmosphere inside of cabinet, purging argon or nitrogen.

After application of drop on semiconductor chip quartz reactor with glass rises upward, as shown arrow in, and platform with diodes upset for on 180° at means of manipulator 18 (Figure 8). The excess of glass flows down, forming under action of surface tension forces optical coating radially symmetrical shape. On Figure 9 is indicated sequence of shaping radial symmetrical shape optical coating after turning semiconductor diode. This method for application of glass ensures good affording shape and reproducibility optical characteristics of sources and receivers of of infrared radiation.

As a result of testing was it is discovered, that at mass of drops of 23-25 g. enhanced best improved integrated optical power and spatial distribution of radiation in 5-10 times.

According to another version of realization, before application of material is semiconductor diode in position, at which its surface, on which is semiconductor chip, faces downwards, and applying of material is by bringing into contact the surface of semiconductor diode with surface of material with provision of wetting this surface of semiconductor diode material. Further is extracted semiconductor diode, and provide drain excessive amount of material. Under the action of surface tension forces is formed optical coating, having radially symmetrical form. Further is made cooling formed optical coating. In subject embodiment of realization of optical coating covers the whole surface of semiconductor diode, on which there is the chip.

According to still one version of realization, is filled with material shape, provided with recess, configuration of which corresponds to the required configuration of optical coating, placed semiconductor diode in position, at which its surface, on which is semiconductor chip, faces downwards, and Be material is by bringing into contact the surface of semiconductor diode with surface of material in said recess, at that cooling optical coating is carried out in said form, after which the semiconductor diode is removed.

Use of glasses of proposed chalcogenide systems allows to increase external quantum yield of the light emitting diode due to the fact, that application of glass reduces angle of full internal reflection, and from chip goes outside exceeds radiation, than in the absence of glass, so-called effect of brightening. Besides is narrowing directivity pattern owing to the shape of glass. Finally photodiode according to the present invention can catch in 10 times larger than optical power.

Chalcogenide glass of proposed systems is low temperature and can be applied on the body of any types: flat, with hollows, for surface mounting (SMD).

The present invention is not limited specific versions realization, opened in description in illustrative purposes, and embraces all possible modification and alternative, included in volume of the present invention, certain the formula of the invention.