Method of fabricating silicon nitride gap-filling layer

• US 8,440,580 B2
• Filed: 09/11/2007
• Issued: 05/14/2013
• 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
• Primary Examiner(s): LUKE, DANIEL M
• Application Number:
  US11/853,475
• Publication Number:
  US 20090068854A1
• Time in Patent Office: 2,072 Days
• Field of Search: 438/761, 438/791, 438/763, 438/778, 438/436
• US Class Current: 438/791
• 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 multi-step formation process to form stacked film layers constituting a dense film, on a substrate;

after performing the multi-step formation process, performing a post single-step deposition process to form a cap layer constituting a sparse film on the stacked film layers; and

performing a curing process to enhance a stress of the cap layer, wherein a thickness of the cured cap layer is greater than a thickness of each of the stacked film layers and is at least about 10% of a total film thickness of the stacked film layers and the cap layer.

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

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

performing a plurality of single-step deposition processes; and

performing a curing process respectively after each single-step deposition process of the multi-step formation process.

5. The method of claim 4, wherein each single-step deposition process of the multi-step formation 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).

6. The method of claim 4, wherein process conditions of each single-step deposition process of the multi-step formation 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.

7. The method of claim 4, wherein process conditions of each curing process of the multi-step formation 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 1000 watts, and an ultra-violet light source of about 100 to 400 nm.

8. The method of claim 4, wherein each film layer of the stacked film layers is a conformal layer.

9. The method of claim 8, wherein each film layer of the stacked film layers is about 100 angstroms to about 500 angstroms thick.

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

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

12. The method of claim 1, wherein process conditions of the 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.

13. The method of claim 1, wherein the stress of each film layer of the stacked film layers is about 1.5 GPa.

14. The method of claim 1, wherein the stress of the cap layer is about 1.2 GPa.

15. The method of claim 4, wherein process conditions of the curing process to enhance a stress of the cap layer 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 1000 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 multi-step formation process and prior to the post single-step deposition process to remove a portion of the dense film.

17. The method of claim 1, wherein the dense film has decreasing stress from a side thereof adjacent to the substrate to another side thereof far away from the substrate.

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

performing a multi-step formation process to form stacked film layers for establishing a dense film, on a substrate, wherein the dense film is consisted of the stacked film layers; and

after performing the multi-step formation process, performing a post single-step deposition process to form a cap layer constituting a sparse film on the dense film; and

performing a curing process to enhance a stress of the cap layer, wherein a thickness of the cap layer is at least about 10% of a total film thickness of the dense film and the cap layer, the thickness of the cured cap layer is larger than a thickness of each of the stacked film layers, and material of the cap layer and material of the stacked film layers are the same.