SILICON NITRIDE GAP-FILLING LAYER AND METHOD OF FABRICATING THE SAME

• US 20090068854A1
• Filed: 09/11/2007
• Published: 03/12/2009
• Est. Priority Date: 09/11/2007
• Status: Active Grant

• Current Assignee: United Microelectronics Corporation
• Original Assignee: United Microelectronics Corporation
• Inventors: Chen, Neng-Kuo, Hsieh, Chao-Ching, Huang, Chien-Chung
• Granted Patent: US 8,440,580 B2
• Time in Patent Office: Days
• US Class Current: 438/792
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/02348 treatment by exposure to UV light
• CPC Class Codes: H01L 21/3185 of siliconnitrides
• CPC Class Codes: H01L 21/76832 Multiple layers
• CPC Class Codes: H01L 21/76837 Filling up the space between adjacent conductive structures; Gap-filling properties of dielectrics
• CPC Class Codes: H01L 21/823412 with a particular manufacturing method of the channel structures, e.g. channel implants, halo or pocket implants, or channel materials
• CPC Class Codes: H01L 29/665 using self aligned silicidation, i.e. salicide formation of conductive layers comprising silicides H01L21/28518
• CPC Class Codes: H01L 29/66545 using a dummy, i.e. replacement gate in a process wherein at least a part of the final gate is self aligned to the dummy gate
• CPC Class Codes: H01L 29/7843 the means being an applied insulating layer

Abstract

A method for fabricating a silicon nitride gap-filling layer is provided. A pre-multi-step formation process is performed to form a stacked layer constituting as a dense film on a substrate. Then, a post-single step deposition process is conducted to form a cap layer constituting as a sparse film on the stacked layer, wherein the cap layer has a thickness of at least 10% of the total film thickness.

Claims

1. A method of fabricating a silicon nitride gap-filling layer, comprising:

performing a pre-multi-step formation process to form a stacked film layer, establishing a dense film, on a substrate; and

performing a post single-step deposition process to form a cap layer, establishing a sparse film on the stacked film layer, wherein a thickness of the cap layer is least about 10% of a total film thickness of the stacked film layer.

2. The method of claim 1, wherein the pre-multi-step formation process comprises:

performing a plurality of pre single-step deposition processes; and

optionally performing a curing process respectively after each pre single-step deposition process.

3. The method of claim 2, wherein each pre single-step deposition process comprises performing atomic layer deposition (ALD), plasma enhanced chemical vapor deposition (PECVD), high density plasma chemical vapor deposition (HDP) or low pressure chemical vapor deposition (LPCVD).

4. The method of claim 2, wherein process conditions of each pre single-step deposition process comprise a flow rate of silane (SiH₄) of about 20 to 2000 sccm, a flow rate of ammonia (NH₃) of about 50 to 10000 sccm, a flow rate of nitrogen (N₂) of about 500 to 30000 sccm, a process temperature of about 200 to 700 degrees Celsius and a high frequency power of radio frequency of about 40 to 3000 watts.

5. The method of claim 2, wherein process conditions of each curing process comprise a process temperature of about 150 to 700 degrees Celsius, a process period of about 10 seconds to 60 minutes, a pressure of about 10 to 760 torrs, an electrical power of about 50 to 10000 watts, and an ultra-violet light source of about 100 to 400 nm.

6. The method of claim 2, wherein each film layer of the stacked film layer is a conformal layer.

7. The method of claim 6, wherein each film layer of the stacked film layer is about 100 angstroms to about 500 angstroms thick.

8. The method of claim 1, wherein the cap layer is about 500 to about 10000 angstroms thick.

9. The method of claim 1, wherein each post single-step deposition process includes performing ALD, PECVD, HDP or LPCVD.

10. The method of claim 1, wherein process conditions of each post single-step deposition process comprises a gas flow rate of silane (SiH₄) of about 20 to 2000 sccm, a flow rate of ammonia (NH₃) of about 50 to 10000 sccm, a flow rate of nitrogen (N₂) of about 500 to 30000 sccm, a process temperature of about 200 to 700 degrees Celsius and a high frequency power of radio frequency of about 40 to 3000 watts.

11. The method of claim 1, wherein a stress of each film layer of the stacked film layer is different from a stress of the cap layer.

12. The method of claim 11, wherein the stress of each film layer of the stacked film layer is about 1.5 GPa.

13. The method of claim 11, wherein the stress of the cap layer is about 1.2 GPa.

14. The method of claim 1, wherein a curing process is optionally performed after performing the post single-step deposition process.

15. The method of claim 14, wherein process conditions of the curing process comprise a process temperature of about 150 to 700 degrees Celsius, a process period of about 10 seconds to 60 minutes, a pressure of about 10 to 760 torrs, an electrical power of about 50 to 10000 watts, and an ultra-violet light source of about 100 to 400 nm.

16. The method of claim 1, wherein an etching process is performed subsequent to the pre-multi-step formation process and prior to the post single-step deposition process to remove a portion of the stacked film layer.

17-23. -23. (canceled)