Silicon-ozone CVD with reduced pattern loading using incubation period deposition

• US 7,994,019 B1
• Filed: 09/27/2010
• Issued: 08/09/2011
• Est. Priority Date: 04/01/2010
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Venkataraman, Shankar, Sapre, Kedar, Gee, Paul Edward, Kweskin, Sasha
• Primary Examiner(s): Stark; Jarrett
• Assistant Examiner(s): Tobergte; Nicholas
• Application Number:
  US12/891,149
• Time in Patent Office: 316 Days
• Field of Search: 438/437, 438/786, 257/296, 257/774
• US Class Current: 438/437
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/45523 Pulsed gas flow or change of composition over time
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD

Abstract

Aspects of the disclosure pertain to methods of depositing conformal silicon oxide layers on patterned substrates. In embodiments, dielectric layers are deposited by flowing a silicon-containing precursor and ozone into a processing chamber such that a relatively uniform dielectric growth rate is achieved across the patterned substrate surface having heterogeneous materials and/or a heterogeneous pattern density distribution. The deposition of dielectric layers grown according to embodiments may have a reduced dependence on underlying material and pattern density while still being suitable for non-sacrificial applications. Reduction in dependence on pattern density is achieved by terminating deposition near the end of an incubation period. Multiple deposition cycles may be conducted in series since the beneficial nature of the incubation period may repeat after a pause in deposition.

Claims

1. A method for forming a conformal silicon oxide layer on a patterned substrate in a substrate processing region in a processing chamber, the method comprising:

a step of depositing a layer of silicon oxide during an incubation period comprising;

initiating flows of a silicon-containing precursor and ozone (O₃) into the substrate processing region, and

terminating the flows of the silicon-containing precursor and ozone near the end of the incubation period to avoid the formation of a nonconformal layer of silicon oxide.

2. The method of claim 1 wherein the patterned substrate has a densely patterned region and a sparsely patterned region and the flows of the silicon-containing precursor and the ozone are terminated such that a thickness of the conformal silicon oxide layer in the densely patterned region is within a conformality percentage of a thickness in the sparsely patterned region.

3. The method of claims 2 wherein the conformality percentage is 30%.

4. The method of claim 1 wherein the patterned substrate has a first exposed material and a second exposed material and the flows of the silicon-containing precursor and the ozone are terminated such that a thickness of the conformal silicon oxide layer deposited on the first exposed material is within a conformality percentage of a thickness deposited on the second exposed material.

5. The method of claims 4 wherein the conformality percentage is 30%.

6. The method of claim 1 wherein the layer of silicon oxide is not conformal at an earlier time during the incubation period but becomes conformal near the end of the incubation period.

7. The method of claim 1 further comprising an additional step of depositing an additional layer of silicon oxide during an additional incubation period.

8. The method of claim 1 wherein a deposition rate during the incubation period is similar on any two of silicon, silicon oxide and silicon nitride.

9. The method of claim 1 wherein a deposition rate on silicon after the incubation period is greater than during the incubation period by a multiplicative factor of 1.3.

10. The method of claim 1 wherein the step of depositing a layer of silicon oxide during an incubation period further comprises flowing water vapor.

11. The method of claim 7 wherein a duration of the additional incubation period is less than a duration of the incubation period.

12. The method of claim 1 wherein terminating the flows of the silicon-containing precursor and ozone near the end of the incubation period comprising terminating the flows of the silicon-containing precursor and ozone at a time selected to achieve a predetermined thickness for the conformal silicon oxide layer.

13. The method of claim 2 wherein an average exposed substantially-vertical area in the densely patterned region exceeds that of the sparsely patterned region by a multiplicative factor of 2.

14. The method of claim 2 wherein the two thicknesses of the conformal silicon oxide layer in the densely and sparsely patterned regions are measured on a substantially-vertical surface of the patterned substrate.

15. The method of claim 2 wherein the two thicknesses of the conformal silicon oxide layer in the densely and sparsely patterned regions are measured on a substantially-horizontal surface of the patterned substrate.

16. The method of claim 1 wherein essentially no plasma is applied to the substrate processing region.

17. The method of claim 1 further comprising the operation of flowing a carrier gas which carries the silicon-containing precursor into the substrate processing region.

18. The method of claim 1 wherein the silicon-containing precursor comprises TEOS.

19. The method of claim 1 further comprising:

a second step of depositing a second conformal layer of silicon oxide on the layer of silicon oxide, wherein the second step comprises;

initiating flows of a silicon-containing precursor and ozone (O₃) into the substrate processing region, and

terminating the flows of the silicon-containing precursor and ozone near the end of the incubation period to avoid the formation of a nonconformal layer of silicon oxide.