OZONE AND TEOS PROCESS FOR SILICON OXIDE DEPOSITION

• US 20090325391A1
• Filed: 06/30/2008
• Published: 12/31/2009
• Est. Priority Date: 06/30/2008
• Status: Abandoned Application

• Current Assignee: ASM International NV
• Original Assignee: ASM International NV
• Inventors: Vandezande, Lieve, Fischer, Pamela R., DE VUSSER, Stijn
• Application Number:
  US12/165,497
• Publication Number:
  US 20090325391A1
• Time in Patent Office: Days
• US Class Current: 438/787
• CPC Class Codes: C23C 16/402 Silicon dioxide
• CPC Class Codes: C23C 16/4412 Details relating to the exhausts, e.g. pumps, filters, scrubbers, particle traps
• CPC Class Codes: C23C 16/4583 the substrate being supported substantially horizontally
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02271 deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition H01L21/02266 takes precedence
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour
• CPC Class Codes: H01L 21/31612 on a silicon body

Abstract

Methods for depositing silicon oxide in a batch reactor are provided. In some embodiments, a plurality of vertically separated substrates is provided in a reaction chamber. Tetraethyl orthosilicate (TEOS) is pulsed into the reaction chamber by direct liquid injection. Ozone is flowed into the reaction chamber simultaneously or alternately with the TEOS. The deposition is performed at about 10 Torr or less to extend the mean free path length of the ozone molecules. According to some embodiments, the deposition allows openings in the substrates to be filled while the occurrence of voids is maintained at a low level.

Claims

1. A method for depositing silicon oxide, comprising:

providing a batch reactor;

providing a plurality of vertically separated substrates in a reaction chamber of the batch reactor;

chemical vapor depositing silicon oxide on the substrates, wherein chemical vapor depositing comprises;

pulsing tetraethyl orthosilicate (TEOS) into the reaction chamber; and

flowing ozone into the reaction chamber while maintaining a pressure inside the reaction chamber at about 10 Torr or less.

2. The method of claim 1, wherein the batch reactor accommodates 25 or more substrates.

3. The method of claim 1, wherein the batch reactor is a hot wall vertical furnace.

4. The method of claim 3, wherein walls of the reaction chamber are formed of quartz.

5. The method of claim 1, wherein the batch reactor comprises at least one injector having vertically spaced apart holes.

6. The method of claim 5, wherein pulsing TEOS comprises injecting TEOS into the reaction chamber out of the vertically spaced apart holes of the injector.

7. The method of claim 5, wherein flowing ozone comprises injecting ozone into the reaction chamber out of vertically spaced apart holes of the injector.

8. The method of claim 5, wherein the ozone is generated before being injected into the reaction chamber.

9. The method of claim 1, wherein pulsing TEOS comprises providing the TEOS to the reaction chamber by direct liquid injection.

10. The method of claim 9, wherein pulsing TEOS comprises providing substantially pure vapor phase TEOS into the reaction chamber.

11. A method for depositing silicon oxide on a substrate, comprising:

providing the substrate in a reaction chamber;

pulsing tetraethyl orthosilicate (TEOS) into the reaction chamber, wherein pulsing TEOS comprises varying the amount of TEOS flowed into the reaction chamber per pulse among a series of the pulses of TEOS;

flowing ozone into the reaction chamber; and

maintaining a pressure inside the reaction chamber at about 10 Torr or less.

12. The method of claim 11, wherein a deposition temperature of the substrate increases over a course of pulsing TEOS into the reaction chamber.

13. The method of claim 12, wherein a pressure of the reaction chamber decreases over a course of pulsing TEOS into the reaction chamber.

14. The method of claim 11, wherein flowing ozone is performed continuously during and between pulses of TEOS into the reaction chamber.

15. The method of claim 14, wherein a rate of flow of ozone into the reaction chamber is constant over the course of pulsing TEOS.

16. The method of claim 14, further comprising varying a rate of flow of ozone into the reaction chamber over the course of pulsing TEOS.

17. The method of claim 14, wherein the rate of flow of ozone into the reaction chamber decreases over the course of pulsing TEOS.

18. The method of claim 11, wherein flowing ozone comprises pulsing ozone into the reaction chamber.

19. The method of claim 18, wherein pulsing ozone and pulsing TEOS comprises providing alternating pulses of ozone and TEOS into the reaction chamber.

20. The method of claim 19, wherein an amount of ozone delivered to the reaction chamber per ozone pulse and an amount of TEOS delivered to the reaction chamber per TEOS pulse are substantially constant over the course of pulsing ozone and pulsing TEOS.

21. The method of claim 19, wherein an amount of TEOS delivered to the reaction chamber per TEOS pulse increases over the course of pulsing ozone and pulsing TEOS.

22. The method of claim 21, wherein an amount of ozone delivered to the reaction chamber per ozone pulse decreases over the course of pulsing ozone and pulsing TEOS.

23. The method of claim 19, further comprising purging the reaction chamber between pulses of TEOS and pulses of ozone.

24. The method of claim 11, wherein pulsing TEOS and flowing ozone comprises:

first, flowing TEOS and ozone into the reaction chamber at a first TEOS;

ozone ratio;

second, flowing TEOS and the ozone into the reaction chamber at a second TEOS;

ozone ratio higher than the first TEOS;

ozone ratio; and

third, flowing TEOS and the ozone into the reaction chamber at a third TEOS;

ozone ratio lower than the second TEOS;

ozone ratio.

25. The method of claim 24, wherein flowing TEOS and ozone into the reaction chamber comprise alternatingly pulsing TEOS and ozone into the reaction chamber, wherein a TEOS pulse and an immediately following ozone pulse define a TEOS:

ozone ratio.

26. A method for depositing silicon oxide, comprising:

providing a substrate in a reaction chamber, the substrate having a trench; and

filling the trench with silicon oxide, wherein filling the trench comprises;

pulsing tetraethyl orthosilicate (TEOS) into the reaction chamber;

flowing ozone into the reaction chamber; and

maintaining a pressure inside the reaction chamber at about 10 Torr or less.

27. The method of claim 26, wherein the trench has an aspect ratio of about four or greater.

28. The method of claim 26, further comprising annealing the substrate after filling the trench.

29. The method of claim 26, wherein filling the trench with silicon oxide comprises filling a bottom portion of the trench at a first temperature set point and a first pressure set point and filling an upper portion of the trench at a second temperature set point and a second pressure set point, wherein the second temperature set point is greater than the first temperature set point.

30. The method of claim 29, wherein the second pressure is greater than the first pressure.

31. The method of claim 26, wherein the pressure inside the reaction chamber is maintained between about 250 mTorr and 2000 mTorr.

32. The method of claim 31, wherein the temperature inside the reaction chamber is maintained between about 550°

C. and 650°

C.