Wafer treatment device and sealing ring for a wafer treatment apparatus

The invention relates to a sealing ring for attachment to a cover ring a wafer-treatment device. Furthermore, the invention pertains to a wafer-treatment device with a receptacle for a wafer, a cover ring is placed on the receptacle, and a sealing ring. The invention relates to a method for manufacturing a sealing ring.

Zum treating wafers irradiating devices are well known, in which the wafer can be treated with a liquid. By the treatment can be modified or processed as such either the wafer, or the liquid can be used, to clean the surface of the wafer.

The liquid applied must be removed again used to treat the wafer, when the treatment step is completed. To this end the receptacle can be rotated together with the wafer, so that the liquid is discharged via a cover ring passes outwards.

In order to fix the wafer in the wafer-treatment device, a vacuum is used. A cover ring is provided, in addition, by means of a seal at the edge region of the wafer or the acts on a component, to which the wafer is temporary fixed, for example, to the carrier film, which in turn is held by a frame. In order to fix the cover ring on the wafer or on the carrier film, a vacuum chamber is provided between the cover ring and the housing, so that a pressing force can be generated, when a vacuum is applied to the vacuum chamber.

The task of the invention is, to ensure a reliable seal between the wafer and the cover ring, so that in particular no liquid into the low pressure chamber or into areas of the wafer, are to be treated can pass which do not, or into the region is received in the the frame of the carrier film.

To solve this problem a sealing ring according to the invention for attachment to a cover ring is provided a wafer-treatment device, with an annular carrier and a sealing lip is mounted detachably on the carrier. To solve the above-mentioned task is also a wafer-treatment device with a receptacle for a wafer, a cover ring is placed on the receptacle, and a sealing ring of the above-mentioned type provided, with which a wafer can be sealed on the receptacle. To solve the above-mentioned task is finally provided a method for manufacturing a sealing ring, in which the following steps are carried out: an annular carrier is provided first of all, on its top with a groove and a radially inwardly sloped bearing surface is provided from the top. Also provided is a sealing lip is provided with a bead, wherein the diameter of the bead and preferably the entire sealing lip in the initial state of the sealing lip is smaller than the diameter of the groove or that of the annular support. The sealing lip is hooked into the groove, so that it extends along the abutment face of the carrier extends beyond the underside of the support and its free end to extend.

The invention is based on the idea, for sealing between the cover ring and the wafer to use a two-part seal, of the carrier and of the sealing lip. The institution shall ensure that the sealing lip is supported over a large area, so that it has the desired shape. Another advantage is that the sealing lip is replaceable, whereby it can be replaced with little expense, if it is worn out or is to be adapted to another application.

Preferably, provided that the sealing lip is hooked into a groove in the carrier. In this way a good seal between the carrier and the sealing lip occurs.

Preferably, the sealing lip on the radially outer side is provided with a bead is hung in the groove. The bead allows, the sealing lip on the carrier mount self-holding, in particular when the bead has a diameter is slightly smaller than the diameter of the groove.

Preferably, provided that the sealing lip from the groove over a part of the upper side of the carrier and extends via a conical contact surface, until it protrudes with its free end beyond the underside of the carrier. In this configuration with its elastic biasing force itself establishes the free end of the seal to the surface of the wafer or on the carrier film, so that it seals it reliably. The seal is not be mechanically pressed against the wafer or the carrier film, but with the bias, which is created by the tentering, pressed against the wafer, so that no undesirably high contact forces may occur.

Preferably, provided that the space between the bearing surface of the support and the sealing lip by means of a channel to a point outside of the sealing lip is vented at the top of the carrier. The channel guaranteed that liquid, despite the contact between the sealing lip and the "behind" the seal passes the wafer or of the carrier film, from there can be discharged reliably.

In accordance with one embodiment of the invention is provided that the carrier is provided with a seal, and can rest on the cover ring. The seal ensures a reliable seal between the annular support and the cover ring, which allows for a the formation of the vacuum chamber the wafer-treatment device.

Preferably, provided that the cover ring is provided with a vent channel is opened to a bearing surface for the seal ring on the cover ring. The ventilation duct allows that part of the liquid, through the channel between the bearing surface of the support and the sealing lip has been removed.

Preferably, provided that the support with the cover ring is screwed. This makes it possible, to release the seal from the cover ring with a small outlay, to exchange, for example, the sealing lip.

In accordance with a preferred embodiment of the invention that the sealing lip after mounting on the carrier or on the cover ring is also cut to size after mounting. This makes it possible for, "cut off" after mounting all tolerance-conditioned dimensional changes of the sealing lip, so that in particular the matching edge of the sealing lip very precise line with the agenda set out in the wafer. Another advantage is that can be adapted by the cutting the sealing lip with a small outlay for the individual customer, without therefor a new, costly mold needs to be established.

Preferably is provided, so that the free end of the sealing lip extends is cut that the front of the sealing lip facing away from the carrier that is perpendicular to the upper side of the carrier or as an upwardly expanding cone. This occurs, when the sealing lip rests on the wafer, a very precise certain, annular contact area having smaller width. Also the end face is, when the sealing lip rests on the wafer, slightly deformed, so that the liquid under the action of the centrifugal force well over the front face of the sealing lip may flow out.

The invention is described below with reference to one embodiment is represented in the accompanying drawings. In these show:

Figure 1 schematically a wafer-treatment device;

In enlarged scale the detail X of Figure 2-Figure 1;

-Figure 2 slightly shifted with respect to the representation of Figure 3 in a sectional plane the detail X of Figure 1;

-the Figures 4a to 4c schematically various steps in the manufacture of the sealing ring;

Figure 5 schematically the contact between sealing lip and wafer;

Figure 6 in a schematic representation the liquid path a second sealing stage ;

and

Figure 7 schematically the range of action of a vacuum pressure applied between cover ring 16 and housing 12.

Figure 1 schematically shows a wafer-treatment apparatus 10 shown, in which a wafer can be treated with a liquid.

The wafers-treatment device 10 has a receptacle 12 on, in which a wafer 14 can be arranged. Located on the receptacle 12 ("tape") can itself or a carrier film the wafer, the wafer is fixed on the 14,16 are sealed by means of a schematically represented cover ring. It the cover ring 18 by applying a vacuum to a vacuum chamber 16 can against the carrier film are acted upon or against the wafer.

On the wafer 14 are applied by means of a schematically shown here can a liquid metering device 20. The liquid can, for example, be used, the surface of the wafer to chemically or physically Edit 14. The liquid can also be used, to clean the surface of the wafer 14.

To can be offset so that the liquid is centrifuged again indicated 14 to be removed from the wafer, the receptacle 12 in rotation (by the arrow R), the liquid under the action of the centrifugal force outwardly. You then collected in a schematically indicated housing 22 is.

To is provided to prevent seals passes that the liquid into the region below the cover ring 16, a sealing ring 24, and the cover ring 14 between the surface of the wafer 16.

Details of the seal between the surface of the wafer 14 or a carrier film, the wafer 14 is disposed on the, and the cover ring 16 be explained below with reference of Figures 2 and 3.

(In Figures 2 and 3 not visible) wafer The 14 is mounted for the purpose of make it easier to handle on a carrier film (also known as "tape") 30,32 is held in a frame the tensioned. The carrier film 34 over the major part of their surface on a support 30 is on is provided in which an annular sealing insert 36.

Zur seal between the wafer 14 and the cover ring 16 to be precise for sealing between the wafer and the cover ring 16 30 14 backing sheet which carries, the sealing ring 24 is provided, the 40 and attached thereto a sealing lip consists of a support 42.

The carrier 44 is mounted detachably to the cover ring 40 by means of a plurality of screws 16. Each screw head of the screws 44 is covered with a cover 46. This prevent that in the area of the screw heads remains liquid.

The carrier 40 is on its upper side, i.e. the side, the bears on the cover ring 16,48 provided with a seal, the seals may be configured similarly to an O-ring 16 and between the carrier 40 and the cover ring.

Radially within the seal 40 is 48 the carrier 50 (see also Figure 4a) provided with a circumferential groove, into which the sealing lip 42 releasably is used. To this end, the sealing lip 42 is provided at its radially outer edge with a bead 52.

Radially within the groove 40 is provided with a conical bearing surface 50 of the carrier 54, on which the sealing lip bears. The sealing lip starting from the groove 42 extends along the contact surface 50 of the carrier thus 54 radially inwards, until they for wafer 14 or 40 protrudes beyond the underside of the carrier 30 towards the carrier film.

The carrier 40 is 56 provided with a pressure-applying rib on its underside, the presses against the sealing insert 36 and the carrier film 36 opposite the sealing insert 30, so that there is sealed.

The carrier 40, a number of channels (the Figures 3 and 4a see) provided 60, below the sealing lip into the groove 42 to the cover 50. The channels in the manner of slots 60 are about 56 guided down (see Figure 3) immediately before the pressure-applying rib.

The channels 60 are intended, derive 50 towards liquid into the groove, the under the sealing lip 42 and pressure-applying rib 42 passes therethrough into the space between sealing lip 56 is. From the groove 62 50 (see Figure 3) by way of a venting channel, this liquid is removed, the radial direction is formed in the cover ring 16 in (at least approximately).

The sealing ring 24 is thereby produced that a separately manufactured sealing lip 50 of the carrier 42 (Figure 4a see) 40 is hooked into the groove. It the bead 42 of the sealing lip 52 is so dimensioned that it has a smaller diameter than the groove 50. In this way the sealing lip 40 on the carrier 42 is resiliently biased (see the state shown in Figure 4b) suspended.

In a next step 42 is radially inner edge of the sealing lip the (see the schematically indicated cut S) trimmed, so that the contour of the sealing lip 42 shown in Figure 4c is obtained at the radially inwardly disposed edge. This contour is distinguished by that the inner end face 64 approximately perpendicular to the top and also extends to the underside of the carrier 40 or conically upwardly opening.

Regardless of the contour of the inner end face 64 can be offset by the cutting of the sealing lip 42, after it is mounted on the carrier 40, a particularly high dimensional accuracy guarantee. The tolerances, in the manufacture of the sealing lip 42 as such occur, are comparatively large. By the cutting of the sealing lip 42 in the finally mounted state all production-related inaccuracies are "simply cut off". Furthermore, starting from one and the same sealing lips-blank different sealing lips can 42 are cut corresponding to customer-specific requirements, without that each time a new mold for producing a matching sealing lip 42 must be provided.

In operation by applying a vacuum to the vacuum chamber 16 is the cover ring 18 against the wafer from the carrier foil 14 or 30 acted upon. Here 42 with its radially inner end, lays down the sealing lip 14 on the wafer 30 on or to the carrier film. 42 is slightly deformed elastically In this way the sealing lip, thereby resulting in the desired 30 result pressure forces on the carrier film.

Due to the specific blank of the inboard edge of the sealing lip 42 arises (in theory) a linear contact, thereby resulting in a rather high contact force results. 42 of the sealing lip 64 is also end wall, which depending on the trimming perpendicular to the upper surface of the support is oriented in the manner of a upwardly widening cone 40 or, slightly deformed, so that an outwardly widening cone is formed.

The sealing lip 42 is a first seal between the cover ring 16 and the wafer 14 or respectively of the carrier foil 30 (and thus also between the carrier 40 and the carrier foil 30) constitute.

Another 16 and the wafer 14 or of the carrier film contact between the cover ring 30 be obtained by the pressure-applying rib 30 to the carrier film in the region of the sealing insert 56 36 presses. This. Elasticity of the sealing insert 36 prevents that the pressure-applying rib 30 exerts 56 inadmissibly high clamping forces to the carrier film.

The pressure-applying rib 16 and the wafer 56 is a second seal between the cover ring 30 constitute 14 or of the carrier film.

If 10 a liquid used during the operation of the wafers-treatment device 14 is to be removed from the wafer, the receptacle 12 is offset in rotation. Suitable rotational velocities are, for example, up to 1500 revolutions per minute. Heat to 14 or of the carrier film on the wafer flows being provided to the liquid 30 passes outwards, so that they have the end face 64, the sealing lip 42 and the adjoining section of the cover ring 16 radially outwardly is discharged above. Den cover ring 16 can (see Figure 2) the liquid then leave through a drain 66.

Falls liquid in the region of the contact point between the sealing lip 42 passes radially under the sealing lip 30 and the carrier film 42, it passes into the space between the sealing lip 42 and the pressure-applying rib 60 is discharged through the passages 56. For this space 50 toward the vent passage it and the groove 62. These is supported thereby that due to the radial orientation of the pipe for communication with a rotation speed of about 500 revolutions per minute above a 62 there is produced reduced pressure.

The channels 60 shall ensure when that no liquid remains before the pressure-applying rib 56, the engage during longer contact 30 could possibly the carrier film. Furthermore is ensured that no liquid can pass into the region is disposed in the frame 32.

The described two-stage sealing system reliably prevented, as far as an area outside of the sealing ring 24 comes that liquid. At first packing stage is a large proportion of liquid by the sealing lip 42 derived. Liquid, the "behind" the sealing lip 42 can pass is then stacked up on the second seal and from there by means of the channels (the pressure-applying rib 56) 60 removed. These is good to see in Figure 6, in which the region is 62 cross-hatched, in which the liquid flows, the passes behind the first seal is.

In Figure 7 the entire vacuum chamber is represented cross-hatched 18, i.e., the region, which can be used to generate, the desired contact pressure between cover ring 16 and housing 12. It is to see that the negative pressure chamber 18 has a very large surface 56 extends from the outer periphery of the receptacle 12 to the pressure-applying rib. Because of the two-stage sealing system is reliably prevented that liquid passes into the low pressure chamber 18.