Pattern enhancement by crystallographic etching
View Patent ↗A method for producing predetermined shapes in a crystalline Si-containing material that have substantially uniform straight sides or edges and well-defined inside and outside corners is provided together with the structure that is formed utilizing the method of the present invention. The inventive method utilizes conventional photolithography and etching to transfer a pattern, i.e., shape, to a crystalline Si-containing material. Since conventional processing is used, the patterns have the inherent limitations of rounded corners. A selective etching process utilizing a solution of diluted ammonium hydroxide is used to eliminate the rounded corners providing a final shape that has substantially straight sides or edges and substantially rounded corners.
1. A semiconductor structure comprising:
a crystalline Si-containing material having at least one pattern located therein, said at least one pattern having substantially uniformly straight sides or edges and substantially square corners, wherein the at least one pattern is on scale with a wavelength of exposure radiation that defined the at least one pattern.
2. The semiconductor structure of claim 1 wherein said crystalline Si-containing material is single crystalline or polycrystalline.
3. The semiconductor structure of claim 1 wherein said crystalline Si-containing material comprises polySi, polySiGe, Si, SiGe, SiC, SiGeC, a silicon-on-insulator or a SiGe-on-insulator.
4. The semiconductor structure of claim 1 wherein said at least one pattern is a trench.
5. The semiconductor structure of claim 2 wherein said trench further comprises a filler material located in a lower portion of said trench.
6. The semiconductor structure of claim 1 wherein remaining crystalline Si-containing material surrounding said at least one pattern forms an active area of a semiconductor device.
7. The semiconductor structure of claim 1 wherein said at least one pattern is an electrically active shape.
8. The semiconductor structure of claim 7 wherein said electrically active shape is a transistor.
9. The semiconductor structure of claim 8 wherein said transistor is a component of a static random access memory cell.
10. The semiconductor structure of claim 1 wherein said crystalline Si-containing material is strained.
11. The semiconductor structure of claim 1 wherein said crystalline Si-containing material contains strained regions and unstrained regions.
12. The semiconductor structure of claim 1 wherein said crystalline Si-containing material has a (100) Miller Index.
13. The semiconductor structure of claim 1 wherein said crystalline Si-containing material has a (110) Miller Index.
14. The semiconductor structure of claim 1 wherein said crystalline Si-containing material has a (111) Miller Index.