Method for fabricating silicon dioxide layer

• US 8,501,636 B1
• Filed: 07/24/2012
• Issued: 08/06/2013
• Est. Priority Date: 07/24/2012
• Status: Active Grant

• Current Assignee: United Microelectronics Corporation
• Original Assignee: United Microelectronics Corporation
• Inventors: Wang, Shao-Wei, Wang, Yu-Ren, Lin, Chien-Liang, Yen, Ying-Wei, Yang, Chih-Wei, Lo, Kun-Yuan
• Primary Examiner(s): Sarkar, Asok K
• Application Number:
  US13/556,247
• Time in Patent Office: 378 Days
• Field of Search: 257/E21.079, 257/E21.082, 257/E21.282, 257/E21.283, 257/E21.284, 257/E21.301, 257/E21.559, 438/585, 438/591, 438/762, 438/765, 438/770, 438/787, 438/906
• US Class Current: 438/787
• CPC Class Codes: H01L 21/02052 Wet cleaning only H01L21/02085 takes precedence
• CPC Class Codes: H01L 21/02238 silicon in uncombined form, i.e. pure silicon
• CPC Class Codes: H01L 21/02255 formation by thermal treatment H01L21/02252 takes precedence; after treatment of an insulating film H01L21/3105 and subgroups
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour
• CPC Class Codes: H01L 21/28167 on single crystalline silicon, e.g. using a liquid, i.e. chemical oxidation
• CPC Class Codes: H01L 21/28185 with a treatment, e.g. annealing, after the formation of the gate insulator and before the formation of the definitive gate conductor
• CPC Class Codes: H01L 21/28202 in a nitrogen-containing ambient, e.g. nitride deposition, growth, oxynitridation, NH3 nitridation, N2O oxidation, thermal nitridation, RTN, plasma nitridation, RPN
• CPC Class Codes: H01L 21/28211 in a gaseous ambient using an oxygen or a water vapour, e.g. RTO, possibly through a layer H01L21/28194 and H01L21/28202 take precedence
• CPC Class Codes: H01L 29/4966 the conductor material next to the insulator being a composite material, e.g. organic material, TiN, MoSi2 H01L29/4908, H01L29/4983 take precedence
• CPC Class Codes: H01L 29/513 the variation being perpendicular to the channel plane
• CPC Class Codes: H01L 29/517 the insulating material comprising a metallic compound, e.g. metal oxide, metal silicate H01L29/518 takes precedence
• 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

Abstract

A method for fabricating silicon dioxide layer is disclosed. The method includes the following steps. Firstly, a semiconductor substrate is provided. Next, the semiconductor substrate is cleaned with a solution containing hydrogen peroxide to form a chemical oxide layer on the semiconductor substrate. Then, the chemical oxide layer is heated in no oxygen atmosphere, such that the chemical oxide layer forms a compact layer. Then, the semiconductor substrate is heated in oxygen atmosphere to form a silicon dioxide layer between the semiconductor substrate and the compact layer.

Claims

1. A method for fabricating silicon dioxide layer, comprising:

providing a semiconductor substrate;

cleaning the semiconductor substrate with a solution containing hydrogen peroxide to form a chemical oxide layer on the semiconductor substrate;

heating the chemical oxide layer in no oxygen atmosphere, such that the chemical oxide layer forms a compact layer; and

heating the semiconductor substrate in oxygen atmosphere to form a silicon dioxide layer between the semiconductor substrate and the compact layer;

wherein the step of cleaning the semiconductor substrate, the step of heating the chemical oxide layer in no oxygen atmosphere, and the step of heating the semiconductor substrate in oxygen atmosphere are performed sequentially.

2. The method for fabricating silicon dioxide layer according to claim 1, wherein the step of heating the chemical oxide layer is completed in a nitrogen atmosphere.

3. The method for fabricating silicon dioxide layer according to claim 1, wherein in the step of heating the chemical oxide layer, the heating temperature ranges between 950˜

1000 degrees Celsius.

4. The method for fabricating silicon dioxide layer according to claim 1, wherein in the step of heating the chemical oxide layer, the heating time ranges between 30˜

60 seconds.

5. The method for fabricating silicon dioxide layer according to claim 1, wherein the solution is formed by hydrogen peroxide, ammonia and de-ionized water at a ratio of 2˜

10;

1;

50.

6. The method for fabricating silicon dioxide layer according to claim 1, wherein the thickness of the compact layer ranges between 2˜

3 Å

.

7. The method for fabricating silicon dioxide layer according to claim 1, further comprising:

forming a high-K layer on the compact layer.

8. The method for fabricating silicon dioxide layer according to claim 1, wherein the density of the compact layer is larger density than that of the chemical oxide layer.

9. A method for fabricating silicon dioxide layer, comprising:

providing a semiconductor substrate;

cleaning the semiconductor substrate with an ozone water solution to form a chemical oxide layer on the semiconductor substrate;

heating the chemical oxide layer in no oxygen atmosphere, such that the chemical oxide layer forms a compact layer; and

heating the semiconductor substrate in oxygen atmosphere to form a silicon dioxide layer between the semiconductor substrate and the compact layer;

wherein the step of cleaning the semiconductor substrate, the step of heating the chemical oxide layer in no oxygen atmosphere, and the step of heating the semiconductor substrate in oxygen atmosphere are performed sequentially.

10. The method for fabricating silicon dioxide layer according to claim 9, wherein the step of heating the chemical oxide layer is completed in a nitrogen atmosphere.

11. The method for fabricating silicon dioxide layer according to claim 9, wherein in the step of heating the chemical oxide layer, the heating temperature ranges between 950˜

1000 degrees Celsius.

12. The method for fabricating silicon dioxide layer according to claim 9, wherein in the step of heating the chemical oxide layer, the heating time ranges between 30˜

60 seconds.

13. The method for fabricating silicon dioxide layer according to claim 9, wherein in the ozone water solution, the concentration of ozone ranges between 60˜

110 ppm.

14. The method for fabricating silicon dioxide layer according to claim 9, wherein the thickness of the compact layer ranges between 2˜

3 Å

.

15. The method for fabricating silicon dioxide layer according to claim 9, further comprising:

forming a high-K layer on the compact layer.

16. The method for fabricating silicon dioxide layer according to claim 9, wherein the density of the compact layer is larger density than that of the chemical oxide layer.