Apparatus and method for surface finishing a silicon film

• US 6,489,241 B1
• Filed: 09/17/1999
• Issued: 12/03/2002
• Est. Priority Date: 09/17/1999
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated, Silicon Genesis
• Original Assignee: Applied Materials Incorporated, Silicon Genesis
• Inventors: Thilderkvist, Anna Lena, Comita, Paul, Scudder, Lance, Riley, Norma
• Primary Examiner(s): Cuneo, Kamand
• Assistant Examiner(s): Zarneke, David A.
• Application Number:
  US09/399,443
• Time in Patent Office: 1,173 Days
• Field of Search: 438/689, 438/706, 438/719, 438/734, 438/964, 438/977, 216/52, 216/58
• US Class Current: 438/689
• CPC Class Codes: C23C 16/0236 by etching with a reactive gas
• CPC Class Codes: C30B 29/06 Silicon
• CPC Class Codes: C30B 33/12 in gas atmosphere or plasma
• CPC Class Codes: H01L 21/02046 Dry cleaning only H01L21/02085 takes precedence
• CPC Class Codes: H01L 21/02381 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02433 Crystal orientation
• CPC Class Codes: H01L 21/0245 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02658 Pretreatments cleaning in general H01L21/02041
• CPC Class Codes: H01L 21/30604 Chemical etching
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/67115 mainly by radiation
• CPC Class Codes: H01L 21/67155 Apparatus for manufacturing or treating in a plurality of work-stations
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond
• CPC Class Codes: Y10S 438/964 Roughened surface
• CPC Class Codes: Y10S 438/977 Thinning or removal of substrate

Abstract

A method of smoothing a silicon surface formed on a substrate. According to the present invention a substrate having a silicon surface is placed into a chamber and heated to a temperature of between 1000°-1300° C. While the substrate is heated to a temperature between 1000°-1300° C., the silicon surface is exposed to a gas mix comprising H₂ and HCl in the chamber to smooth the silicon surface.

Claims

1. A method of treating a silicon or silicon alloy surface of a substrate, said method comprising the steps of:

heating a substrate having a silicon or silicon alloy surface in a chamber to a temperature of between 1000°

-1300°

C.;

introducing a first gas comprising HCl into said chamber through a plurality of zones, wherein the flow rate of said first gas in each zone is independently controllable; and

exposing said silicon or silicon alloy surface to said first gas in said chamber while heating said substrate.

2. The method of claim 1 wherein said temperature is between 1050°

-1200°

C.

3. The method of claim 1 further comprising the step of:

after exposing said silicon or silicon alloy surface to said first gas, depositing in said chamber a silicon film on said silicon or silicon alloy surface of said substrate.

4. The method of claim 1 wherein said silicon or silicon alloy surface has a surface roughness of at least 0.2 nm RMS prior to exposing said substrate to said first gas.

5. The method of claim 4 wherein said substrate is exposed to said first gas until said silicon or silicon alloy has a surface roughness of less than 0.1 nm.

6. The method of claim 1 wherein said first gas further comprises H₂.

7. The method of claim 1 wherein the pressure within said chamber while exposing said substrate to said first gas is atmospheric pressure.

8. The method of claim 6 wherein said first gas has a molecular concentration ratio of HCl to H₂ of between 1:

100 to 1;

1000.

9. The method of claim 6 further comprising the steps of after exposing said silicon or silicon alloy surface to said first gas, exposing said silicon or silicon alloy surface to a second gas comprising HCl and H₂ while heating said substrate.

10. The method of claim 9 wherein said second gas has a different molecular concentration ratio of HCl to H₂ than said first gas.

11. The method of claim 1 wherein said silicon or silicon alloy surface is a silicon or silicon alloy film formed on an oxide film formed on a single crystalline silicon substrate.

12. A method of treating a silicon or silicon alloy surface formed on a substrate, said method comprising the steps of:

heating a substrate having a silicon or silicon alloy surface in a chamber to a temperature of between 1000°

-1300°

C.;

introducing a gas comprising H₂ and HCl into said chamber through a plurality of zones, wherein the flow rate of said gas in each zone is independently controllable;

exposing said silicon or silicon alloy surface to said gas in said chamber while heating said substrate; and

depositing in said chamber a silicon film onto said H₂ and HCl exposed silicon or silicon alloy surface.

13. A method of treating a silicon or silicon alloy surface on a substrate, said method comprising the steps of:

heating a substrate having a silicon or silicon alloy surface in a chamber to a temperature of between 1000°

-1300°

C.;

exposing said silicon or silicon alloy surface to a first gas comprising HCl and H₂ while heating said substrate, wherein said first gas has a first molecular concentration ratio of HCl to H₂; and

exposing said silicon or silicon alloy surface to a second gas comprising HCl and H₂ while heating said substrate, wherein said second gas has a lower molecular concentration ratio of HCl to H₂ than said first gas.

14. A method of treating the surface of a silicon or silicon alloy film on a silicon on insulator substrate, said method comprising the steps of:

heating said substrate in a chamber to a temperature between 1050°

-1200°

C.;

exposing said silicon or silicon alloy film to a first gas comprising HCl and H₂ in said chamber while heating said substrate, wherein said first gas has a molecular concentration ratio of HCl to H₂ between 1;

100 to 1;

1000;

exposing said silicon or silicon alloy film to a second gas comprising HCl and H₂ in said chamber while heating said substrate, wherein said second gas has a molecular concentration ratio of HCl to H₂ between 1;

100 to 1;

1000 and wherein said second gas has a molecular concentration ratio of HCl to H₂ which is lower than the molecular concentration ratio of HCl to H₂ of said first gas; and

after exposing said silicon film to said second gas, depositing in said chamber a second silicon film on said silicon or silicon alloy film of said silicon on insulator substrate.

15. A method for treating a surface of a substrate, said method comprising:

providing a chamber with a plurality of gas inlet zones, wherein the gas flow rate in each gas inlet zone is independently controllable;

providing a substrate within said chamber, said substrate comprising a cleaved surface, said cleaved surface being characterized by a predetermined surface roughness value and having a distribution of hydrogen bearing particles defined from said cleaved surface to a region underlying said cleaved surface;

increasing a temperature of said cleaved surface to greater than about 1000°

C. while introducing a hydrogen bearing etchant gas into said chamber through said gas inlet zones; and

exposing said cleaved surface to said hydrogen bearing etchant gas, thereby reducing said predetermined surface roughness value by about fifty percent and greater.

16. The method of claim 15 wherein said hydrogen bearing etchant gas comprises HCl and H₂.

17. The method of claim 16 wherein the molecular concentration ratio of HCl to H₂ in said hydrogen bearing etchant gas is about 1:

1000.

18. The method of claim 16 wherein the molecular concentration ratio of HCl to H₂ in said hydrogen bearing etchant gas is about 1:

1000 and greater.

19. The method of claim 15 wherein said substrate is maintained at about 1 atmosphere during said treatment.

20. The method of claim 15 wherein said cleaved surface is provided by a controlled cleave process.

21. The method of claim 15 wherein said substrate is a silicon wafer.

22. A method of treating a silicon or silicon alloy surface of a substrate, said method comprising the steps of:

heating a substrate having a silicon or silicon alloy surface in a chamber to a temperature of between 1000°

-1300°

C.;

introducing a gas comprising HCl and H₂ into said chamber, wherein the gas has a molecular concentration ratio of HCl to H₂ of between 1;

100 to 1;

1000; and

exposing said silicon or silicon alloy surface to said gas in said chamber while heating said substrate.