Claims
- 1. A semiconductor assembly comprising:a semiconductor substrate having a dielectric layer thereover; a doped active-device region in said semiconductor substrate; at least one opening extending through said dielectric layer and into said doped active-device region in said semiconductor substrate; a halide-containing boundary layer coating exposed surfaces of said at least one opening, said halide-containing boundary being adapted for self-limiting removal of a portion of said doped active region when halides in said halide-containing boundary layer are exposed to ion bombardment, wherein the amount of the removed portion of said doped active region is proportional to a thickness of said halide containing boundary layer at the bottom of said at least one opening.
- 2. The semiconductor assembly of claim 1, wherein said halide-containing boundary layer comprises at least one element selected from the group of fluorine, chlorine, bromine, iodine, and astatine.
- 3. The semiconductor assembly of claim 1, wherein said halide-containing boundary layer has a thickness of from about 50 angstroms to about 250 angstroms.
- 4. The semiconductor assembly of claim 1, wherein said halide-containing boundary layer has a thickness of from about 200 angstroms to about 250 angstroms.
- 5. The semiconductor assembly of claim 1, wherein said halide-containing boundary layer comprises a continuous layer.
- 6. The semiconductor assembly of claim 1, wherein said halide-containing boundary layer comprises a discontinuous layer.
- 7. The semiconductor assembly of claim 1, wherein said semiconductor substrate comprises a silicon substrate.
- 8. The semiconductor assembly of claim 7, wherein said semiconductor substrate comprises a silicon wafer.
- 9. A semiconductor assembly comprising:a semiconductor substrate having a dielectric layer thereover; a doped active-device region in said semiconductor substrate; said doped active-device region having a dopant-depleted portion; at least one opening extending through said dielectric layer and into a doped active-device region in said semiconductor substrate; and a halide-containing boundary layer coating exposed surfaces of said at least one opening, wherein a residual of said dopant-depleted potion of said doped active-device region is resistant to removal by ion bombardment when halides within said halide-containing boundary are activated and depleted by ion bombardment, and the amount of a removed portion of said dopant depleted portion is proportional to a thickness of said halide containing boundary layer at the bottom of said at least one opening.
- 10. The semiconductor assembly of claim 9, wherein said halide-containing boundary layer comprises at least one element selected from the group of fluorine, chlorine, bromine, iodine, and astatine.
- 11. The semiconductor assembly of claim 9, wherein said halide-containing boundary layer has a thickness of from about 50 angstroms to about 250 angstroms.
- 12. The semiconductor assembly of claim 9, wherein said halide-containing boundary layer has a thickness of from about 200 angstroms to about 250 angstroms.
- 13. The semiconductor assembly of claim 9, wherein said halide-containing boundary layer comprises a continuous layer.
- 14. The semiconductor assembly of claim 9, wherein said halide-containing boundary layer comprises a discontinuous layer.
- 15. The semiconductor assembly of claim 9, wherein said semiconductor substrate comprises a silicon substrate.
- 16. The semiconductor assembly of claim 15, wherein said semiconductor substrate comprises a silicon substrate.
CROSS REFERENCE TO RELATED APPLICATION
This application is a divisional of application Ser. No. 09/082,138, filed May 20, 1998. now U.S. Pat. No. 6,232,219.
US Referenced Citations (16)