Control of solid state dimensional features
(19)AUSTRALIAN PATENT OFFICE (54) Title Control of solid state dimensional features (51)6 International Patent Classification(s) H01L 021/66 B8IB 001/00 B81C 005/00 H01J 037/32 (21) Application No: 2002315497 (22) Application Date: 2002 .06.27 (87) WIPO No: WO03/003446 (30) Priority Data (31) Number (32) Date 60/301,400 2001 .06.27 (33) Country US 200510207 (43) (43) Publication Date : 2003 .03.03 Publication Journal Date : 2003 .05.15 (71) Applicant(s) PRESIDENT AND FELLOWS OF HARVARD COI 1 FGE (72) Inventor(s) Golovchenko, Jene A.; Stein, Derek M.: J.; Li, Jiali A solid state structure having a surface is provided and is exposed to a flux, F , of incident ions. The conditions of this incident ion exposure are selected based on (I) where C is conc entration of mobile adatoms at structure surface, r is vector surface position, t is time, <i >Y 1 is number of adatoms created per incident ion, D is adatom diffusivity, tau trap is average lifetime of an adatom before adatom annihilation occurs at a structure surface defect characteristic of solid state structure material, and sigma c is cross-section for adatom annihilation by incident ions characteristic of selected ion exposure conditions. Ion exposure condition selection controls sputtering of the structure surface by incident ions to transport, within the structure including the structure surface, material of the structure to a feature location, in response to the ion flux exposure, to produce a feature substantially by locally adding material of the structure to the feature location. A method for fabricating a feature of a solid state structure (10) comprising the steps of: providing a solid state structure (10) having a surface;
prespecifying the feature to be fabricated and a location of the structure at which the feature is to be fabricated;
exposing the structure to a flux, The feature fabrication method of claim 1, wherein selection of ion exposure conditions comprises selection of incident ion energy, incident ion species, incident ion flux, The feature fabrication method of claim 1 or 2, wherein selection of ion exposure conditions comprises: carrying out at least one test incident ion exposure of the solid state structure material under selected test incident ion exposure conditions; directing a physical detection species toward a designated structure location during each test incident ion exposure; detecting the detection species in a trajectory from the designated structure location to indicate feature fabrication dependence on the test ion exposure conditions; and selecting the ion exposure conditions based on the test ion exposure conditions and the corresponding indicated feature fabrication dependence on the test ion exposure conditions. The feature fabrication method of claim 1 or 2, wherein the solid state structure (10) includes an edge boundary location and wherein the selected feature location comprises a relocated edge boundary location fabricated by the ion flux exposure. The feature fabrication method of claim 4, wherein the solid state structure (10) comprises an aperture having an edge and wherein the relocated edge boundary location comprises a relocated aperture edge fabricated by the ion flux exposure.