METHOD FOR MANUFACTURING SHALLOW TRENCH ISOLATION

• US 20090017597A1
• Filed: 01/04/2008
• Published: 01/15/2009
• Est. Priority Date: 07/11/2007
• Status: Abandoned Application

• Current Assignee: ProMOS Technologies, Inc.
• Original Assignee: ProMOS Technologies, Inc.
• Inventors: LIU, YU SHENG, ZHAO, PETER HAI JUN, CHEN, YU CHI
• Application Number:
  US11/969,726
• Publication Number:
  US 20090017597A1
• Time in Patent Office: Days
• US Class Current: 438/432
• CPC Class Codes: H01L 21/3115 Doping the insulating layers
• CPC Class Codes: H01L 21/76224 using trench refilling with dielectric materials trench filling with polycristalline silicon H01L21/763; together with vertical isolation, e.g. trench refilling in a SOI substrate H01L21/76264
• CPC Class Codes: H01L 21/76229 Concurrent filling of a plurality of trenches having a different trench shape or dimension, e.g. rectangular and V-shaped trenches, wide and narrow trenches, shallow and deep trenches
• CPC Class Codes: H01L 21/76237 introducing impurities in trench side or bottom walls, e.g. for forming channel stoppers or alter isolation behavior

Abstract

A method for manufacturing semiconductor shallow trench isolation is performed as follows. First, a semiconductor substrate including at least one shallow trench is provided, and the shallow trench is filled with Spin-On-Dielectric (SOD) material, e.g., polysilazane, to form a SOD material layer. Then, the SOD material layer is subjected to a planarization process. Oxygen ions are implanted into the SOD material layer to a predetermined depth, and a high temperature process is performed afterwards to transform the portion of the SOD material layer having oxygen ions into a silicon oxide layer. The oxygen ions can be implanted by plasma doping, immersion doping or ion implantation.

Claims

1. A method for manufacturing shallow trench isolation, comprising:

providing a semiconductor substrate including at least one shallow trench;

depositing spin-on-dielectric (SOD) material in the shallow trench to form a SOD material layer;

planarizing the SOD material layer;

implanting oxygen ions into the SOD material layer to a first predetermined depth; and

performing a high temperature process to transform the portion of the SOD material layer having oxygen ions into a silicon oxide layer.

2. The method of claim 1, wherein the SOD material comprises polysilazane or perhydro-polysilazane.

3. The method of claim 1, wherein the oxygen ions are implanted by plasma doping, immersion doping or ion implantation.

4. The method of claim 1, wherein the first predetermined depth is between 100 and 1000 angstroms.

5. The method of claim 1, wherein the first predetermined depth is between 100 and 200 angstroms.

6. The method of claim 1, wherein the dosage of implanting oxygen ions is greater than 1E17 atoms/cm².

7. The method of claim 1, wherein the energy of implanting oxygen ions is between 0.5 KeV and 10 KeV.

8. The method of claim 1, further comprising a step of forming an oxide layer on the shallow trench before depositing SOD material.

9. The method of claim 1, wherein the oxygen ions are diffused to a second predetermined depth in the high temperature process, and the second predetermined depth is larger than the first predetermined depth.

10. The method of claim 1, wherein the high temperature process is performed in a nitrogen environment.

11. The method of claim 1, wherein the high temperature process is performed at a temperature higher than 950°

C.

12. The method of claim 1, wherein the high temperature process is a rapid temperature processing or a decoupled plasma nitrification.

13. The method of claim 1, wherein the high temperature process is performed without steam.