Manufacturing method of epitaxial contact structure in semiconductor memory device

• US 10,151,048 B1
• Filed: 11/29/2017
• Issued: 12/11/2018
• Est. Priority Date: 11/10/2017
• Status: Active Grant

• Current Assignee: Fujian Jinhua Integrated Circuit Co., Ltd., United Microelectronics Corporation
• Original Assignee: Fujian Jinhua Integrated Circuit Co., Ltd., United Microelectronics Corporation
• Inventors: Wu, Wan-Chi, Chuang, Hui-Ling, Cheng, Chih-Chi, Yeh, Chiu-Hsien, Tsai, Chien-Cheng, Yan, Hung-Jung
• Primary Examiner(s): Amer, Mounir S
• Application Number:
  US15/825,127
• Time in Patent Office: 377 Days
• Field of Search: None
• CPC Class Codes: C30B 25/186 being specially pre-treated by, e.g. chemical or physical means
• CPC Class Codes: G11C 11/4094 Bit-line management or control circuits
• CPC Class Codes: G11C 11/4097 Bit-line organisation, e.g. bit-line layout, folded bit lines
• CPC Class Codes: H01L 21/02057 Cleaning during device manufacture
• CPC Class Codes: H01L 21/02293 formation of epitaxial layers by a deposition process epitaxial growth per se C30B
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02639 Preparation of substrate for selective deposition
• CPC Class Codes: H10B 12/01 Manufacture or treatment
• CPC Class Codes: H10B 12/09 with simultaneous manufacture of the peripheral circuit region and memory cells
• CPC Class Codes: H10B 12/485 Bit line contacts

Abstract

A manufacturing method of an epitaxial contact structure in a semiconductor memory device includes the following steps. A recess is formed in a semiconductor substrate by an etching process. An etching defect is formed in the recess by the etching process. An oxidation process is performed after the etching process. An oxide layer is formed in the recess by the oxidation process, and the etching defect is encompassed by the oxide layer. A cleaning process is performed after the oxidation process. The oxide layer and the etching defect encompassed by the oxide layer are removed by the cleaning process. An epitaxial growth process is performed to form an epitaxial contact structure in the recess after the cleaning process.

Claims

1. A manufacturing method of an epitaxial contact structure in a semiconductor memory device, comprising:

forming a recess in a semiconductor substrate by an etching process, wherein an etching defect is formed in the recess by the etching process;

performing an oxidation process after the etching process, wherein an oxide layer is formed in the recess by the oxidation process, and the etching defect is encompassed by the oxide layer;

performing a cleaning process after the oxidation process, wherein the oxide layer and the etching defect encompassed by the oxide layer are removed by the cleaning process; and

performing an epitaxial growth process to form an epitaxial contact structure in the recess after the cleaning process, wherein the oxidation process and the cleaning process are performed repeatedly before the epitaxial growth process.

2. The manufacturing method of the epitaxial contact structure in the semiconductor memory device according to claim 1, wherein an oxidation agent used in the oxidation process comprises hydrogen peroxide (H₂O₂) or ozone (O₃) water.

3. The manufacturing method of the epitaxial contact structure in the semiconductor memory device according to claim 1, wherein the cleaning process comprises a dry cleaning process.

4. The manufacturing method of the epitaxial contact structure in the semiconductor memory device according to claim 3, wherein a process gas used in the dry cleaning process comprises nitrogen trifluoride (NF₃).

5. The manufacturing method of the epitaxial contact structure in the semiconductor memory device according to claim 1, wherein the cleaning process comprises a standard clean 1 (SC1) process or a dilute hydrogen fluoride (DHF) cleaning process.

6. The manufacturing method of the epitaxial contact structure in the semiconductor memory device according to claim 1, further comprising:

performing a pre cleaning process before the oxidation process, wherein the pre cleaning process is different from the oxidation process.

7. The manufacturing method of the epitaxial contact structure in the semiconductor memory device according to claim 6, wherein the pre cleaning process comprises a piranha clean (SPM clean) process, a SC1 process, or a DHF cleaning process.

8. The manufacturing method of the epitaxial contact structure in the semiconductor memory device according to claim 1, wherein the etching defect comprises a non-silicon impurity or a silicon damage layer.

9. The manufacturing method of the epitaxial contact structure in the semiconductor memory device according to claim 1, further comprising:

forming a plurality of bit line structures on the semiconductor substrate.

10. The manufacturing method of the epitaxial contact structure in the semiconductor memory device according to claim 9, wherein the recess and the epitaxial contact structure are formed before the step of forming the bit line structures, and one of the bit line structures is electrically connected with the epitaxial contact structure.

11. The manufacturing method of the epitaxial contact structure in the semiconductor memory device according to claim 9, wherein the recess and the epitaxial contact structure are formed after the step of forming the bit line structures.

12. The manufacturing method of the epitaxial contact structure in the semiconductor memory device according to claim 11, wherein the epitaxial contact structure is electrically isolated from the bit line structures.

13. The manufacturing method of the epitaxial contact structure in the semiconductor memory device according to claim 11, wherein the epitaxial contact structure comprises a storage node contact structure.

14. A manufacturing method of an epitaxial contact structure in a semiconductor memory device, comprising:

forming a recess in a semiconductor substrate by an etching process, wherein an etching defect is formed in the recess by the etching process;

performing an oxidation process after the etching process, wherein an oxide layer is formed in the recess by the oxidation process, and the etching defect is encompassed by the oxide layer;

performing a cleaning process after the oxidation process, wherein the oxide layer and the etching defect encompassed by the oxide layer are removed by the cleaning process;

performing an epitaxial growth process to form an epitaxial contact structure in the recess after the cleaning process; and

performing a pre cleaning process before the oxidation process, wherein the pre cleaning process is different from the oxidation process.

15. The manufacturing method of the epitaxial contact structure in the semiconductor memory device according to claim 14, wherein an oxidation agent used in the oxidation process comprises hydrogen peroxide (H₂O₂) or ozone (O₃) water.

16. The manufacturing method of the epitaxial contact structure in the semiconductor memory device according to claim 14, wherein the cleaning process comprises a dry cleaning process.

17. The manufacturing method of the epitaxial contact structure in the semiconductor memory device according to claim 16, wherein a process gas used in the dry cleaning process comprises nitrogen trifluoride (NF₃).

18. The manufacturing method of the epitaxial contact structure in the semiconductor memory device according to claim 14, wherein the cleaning process comprises a standard clean 1 (SC1) process or a dilute hydrogen fluoride (DHF) cleaning process.

19. The manufacturing method of the epitaxial contact structure in the semiconductor memory device according to claim 14, wherein the pre cleaning process comprises a piranha clean (SPM clean) process, a SC1 process, or a DHF cleaning process.

20. A manufacturing method of an epitaxial contact structure in a semiconductor memory device, comprising:

forming a recess in a semiconductor substrate by an etching process, wherein an etching defect is formed in the recess by the etching process;

performing an oxidation process after the etching process, wherein an oxide layer is formed in the recess by the oxidation process, and the etching defect is encompassed by the oxide layer;

performing a cleaning process after the oxidation process, wherein the oxide layer and the etching defect encompassed by the oxide layer are removed by the cleaning process;

performing an epitaxial growth process to form an epitaxial contact structure in the recess after the cleaning process; and

forming a plurality of bit line structures on the semiconductor substrate, wherein the recess and the epitaxial contact structure are formed after the step of forming the bit line structures.