Patent ID: 6794296
Filing Date: 2004-09-21
Classification: B81B,B81C,G01Q,G02B,H01J

Abstract:
Method for producing an aperture (10) in a semiconductor material (12) comprising the following steps:preparing a semiconductor wafer (14) having an upper surface (16) and lower surface (18), producing a cavity (20) with oriented side walls (22) in the upper surface (16) of the semiconductor wafer (14) by means of partially etching said upper surface (16) anisotropically, wherein the cavity (20) comprises a closed bottom area (24) facing the lower surface (18) having a convex or concave corner or edge separating at least two side walls with different orientation, depositing an oxide layer (26) on the semiconductor material (12) at least in the bottom area of the cavity (20) by oxidizing the semiconductor material (12), where the oxide layer (26) at least in the bottom area (24) comprises an inhomogeneity (28) located in the proximity of the convex or concave corner or edge, selectively etching back the semiconductor material (12) on the lower surface (18) of the semiconductor wafer (14) until at least the oxide layer (26) located in the bottom area (24) is exposed, and etching the exposed oxide layer (26) until it is at least severed at the inhomogeneity (28) thereby producing an aperture (70) having a size which is substantially determined by the location of the inhomogeneity (28).