Method of forming a structure over a semiconductor substrate

• US 7,803,678 B2
• Filed: 06/25/2008
• Issued: 09/28/2010
• Est. Priority Date: 06/22/2000
• Status: Expired due to Fees

• Current Assignee: Round Rock Research LLC
• Original Assignee: Round Rock Research LLC
• Inventors: Moore, John T., Beaman, Kevin L.
• Primary Examiner(s): Smoot; Stephen W
• Application Number:
  US12/145,772
• Publication Number:
  US 20080261388A1
• Time in Patent Office: 825 Days
• Field of Search: 257/E21.267
• US Class Current: 438/216
• CPC Class Codes: H01L 21/823842 gate conductors with different gate conductor materials or different gate conductor implants, e.g. dual gate structures
• CPC Class Codes: H01L 21/823857 with a particular manufacturing method of the gate insulating layers, e.g. different gate insulating layer thicknesses, particular gate insulator materials or particular gate insulator implants
• CPC Class Codes: H10B 41/49 comprising different types of peripheral transistor
• CPC Class Codes: Y10S 257/90 MOSFET type gate sidewall insulating spacer

Abstract

The invention includes a method of forming a structure over a semiconductor substrate. A silicon dioxide containing layer is formed across at least some of the substrate. Nitrogen is formed within the silicon dioxide containing layer. Substantially all of the nitrogen within the silicon dioxide is at least 10Å above the substrate. After the nitrogen is formed within the silicon dioxide layer, conductively doped silicon is formed on the silicon dioxide layer.

Claims

1. A method of forming a structure over a semiconductor substrate, comprising:

providing the semiconductor substrate, the substrate comprising a first region and a second region, the first region comprising a differently-doped region than the second region;

forming a first oxide layer over the first and second regions;

providing nitrogen into at least a portion of the first oxide layer over the first region;

forming a first conductive layer over the first oxide layer and over the first and second regions;

providing a masking layer against the first conductive layer; and

forming a second oxide layer over the first and second regions.

2. The method of claim 1 further comprising removing the first conductive layer from over the second region before the forming of the second oxide layer.

3. The method of claim 1 further comprising:

forming a second conductive layer over the first and second regions; and

removing the first conductive layer from over the second region before the forming of the second conductive layer.

4. The method of claim 1 wherein the forming of the second oxide layer comprises forming the second oxide layer against the first conductive layer.

5. The method of claim 1 further comprising forming a second conductive layer over the first and second regions.

6. A method of forming a structure over a semiconductor substrate, comprising:

providing the semiconductor substrate, the substrate comprising a first region and a second region, the first region comprising a differently-doped region than the second region;

providing an oxide layer over the first and second regions, the oxide layer comprising a thickness extending generally perpendicularly from the substrate;

while maintaining the same thickness of the oxide layer over the first and second regions, forming a conductive layer against the oxide layer and over the first and second regions; and

providing nitrogen into the oxide layer and leaving nitrogen in only the oxide layer over the first region.

7. The method of claim 6 further comprising forming another oxide layer over the first and second regions.

8. The method of claim 6 further comprising forming another conductive layer over the first and second regions.

9. The method of claim 6 further comprising forming a masking layer against the conductive layer, the masking layer being over the first region and not over the second region.

10. The method of claim 6 further comprising:

forming another oxide layer over the first and second regions; and

forming another conductive layer over the another oxide layer and over the first and second regions.

11. The method of claim 6 wherein the first region comprises a n-type doped region and the second region comprises a p-type doped region.

12. A method of forming a structure over a semiconductor substrate, comprising:

providing the semiconductor substrate, the substrate comprising a first region and a second region, the first region comprising a different area of the substrate than the second region;

providing a first oxide layer over the first region, the first oxide layer comprising a first thickness extending generally perpendicularly relative the substrate;

without providing a masking layer against the first oxide layer, providing a second oxide layer over the second region, the second oxide layer comprising a second thickness extending generally perpendicularly relative the substrate, the second thickness being greater than the first thickness of the first oxide layer;

providing nitrogen into the first oxide layer; and

providing a conductive layer against the first and second oxide layers, the conductive layer comprising a thickness extending generally perpendicularly relative the substrate, the thickness of the conductive layer over the first region being substantially equal to the thickness of the conductive layer over the second region.

13. The method of claim 12 wherein the first oxide layer further comprises an upper portion and a lower portion, the upper portion comprising an upper surface and being spaced from the semiconductor substrate by the lower portion, and wherein the providing of the nitrogen comprises providing substantially all of the nitrogen within the upper portion.

14. The method of claim 12 wherein the first oxide layer further comprises an upper portion and a lower portion, the upper portion comprising an upper surface and being spaced from the semiconductor substrate by the lower portion, and wherein the providing of the nitrogen comprises no measurable amount of the nitrogen within the lower portion.

15. The method of claim 14 wherein the lower portion of the first oxide layer comprises a thickness of about 10 angstroms.

16. The method of claim 14, wherein the upper portion of the first oxide layer comprises a thickness of about 10 angstroms.

17. The method of claim 12 wherein the providing of the nitrogen comprises:

forming an activated nitrogen species comprising a first energy state;

changing the first energy state of the activated nitrogen species to a second energy state that is different from the first energy state; and

exposing the first oxide layer to the activated nitrogen species at the second energy state.

18. The method of claim 17 wherein the second energy state is a lower energy state than the first energy state.

19. A method of forming a structure over a semiconductor substrate, comprising:

providing the semiconductor substrate, the substrate comprising a first region and a second region, the first region comprising a different area of the substrate than the second region;

providing a first oxide layer over the first region, the first oxide layer comprising a first thickness extending generally perpendicularly relative the substrate;

providing a second oxide layer over the second region, the second oxide layer comprising a second thickness extending generally perpendicularly relative the substrate, the second thickness being greater than the first thickness of the first oxide layer;

providing nitrogen into the first oxide layer;

providing a conductive layer against the first and second oxide layers, the conductive layer comprising a thickness extending generally perpendicularly relative the substrate, the thickness of the conductive layer over the first region being substantially equal to the thickness of the conductive layer over the second region; and

wherein the first oxide layer further comprises an upper portion and a lower portion, the upper portion comprising an upper surface and being spaced from the semiconductor substrate by the lower portion, and wherein the providing of the nitrogen comprises providing substantially all of the nitrogen within the upper portion.

20. A method of forming a structure over a semiconductor substrate, comprising:

providing the semiconductor substrate, the substrate comprising a first region and a second region, the first region comprising a different area of the substrate than the second region;

providing a first oxide layer over the first region, the first oxide layer comprising a first thickness extending generally perpendicularly relative the substrate;

providing a second oxide layer over the second region, the second oxide layer comprising a second thickness extending generally perpendicularly relative the substrate, the second thickness being greater than the first thickness of the first oxide layer;

providing nitrogen into the first oxide layer;

providing a conductive layer against the first and second oxide layers, the conductive layer comprising a thickness extending generally perpendicularly relative the substrate, the thickness of the conductive layer over the first region being substantially equal to the thickness of the conductive layer over the second region; and

wherein the first oxide layer further comprises an upper portion and a lower portion, the upper portion comprising an upper surface and being spaced from the semiconductor substrate by the lower portion, and wherein the providing of the nitrogen comprises no measurable amount of the nitrogen within the lower portion.

21. The method of claim 20 wherein the lower portion of the first oxide layer comprises a thickness of about 10 angstroms.

22. The method of claim 20, wherein the upper portion of the first oxide layer comprises a thickness of about 10 angstroms.

23. A method of forming a structure over a semiconductor substrate, comprising:

providing the semiconductor substrate, the substrate comprising a first region and a second region, the first region comprising a different area of the substrate than the second region;

providing a first oxide layer over the first region, the first oxide layer comprising a first thickness extending generally perpendicularly relative the substrate;

providing a second oxide layer over the second region, the second oxide layer comprising a second thickness extending generally perpendicularly relative the substrate, the second thickness being greater than the first thickness of the first oxide layer;

providing nitrogen into the first oxide layer;

providing a conductive layer against the first and second oxide layers, the conductive layer comprising a thickness extending generally perpendicularly relative the substrate, the thickness of the conductive layer over the first region being substantially equal to the thickness of the conductive layer over the second region; and

wherein the providing of the nitrogen comprises;

forming an activated nitrogen species comprising a first energy state;

changing the first energy state of the activated nitrogen species to a second energy state that is different from the first energy state; and

exposing the first oxide layer to the activated nitrogen species at the second energy state.

24. The method of claim 23 wherein the second energy state is a lower energy state than the first energy state.