Method of fabricating semiconductor device

• US 10,170,623 B2
• Filed: 10/30/2017
• Issued: 01/01/2019
• Est. Priority Date: 07/20/2015
• Status: Active Grant

• Current Assignee: United Microelectronics Corporation
• Original Assignee: United Microelectronics Corporation
• Inventors: Liou, En-Chiuan, Weng, Tang-Chun, Chen, Chien-Hao
• Primary Examiner(s): Dinke, Bitew A
• Application Number:
  US15/796,874
• Publication Number:
  US 20180047848A1
• Time in Patent Office: 428 Days
• CPC Class Codes: H01L 29/0653 adjoining the input or output region of a field-effect device, e.g. the source or drain region
• 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 29/66795 with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 29/785 having a channel with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 29/7851 with the body tied to the substrate

Abstract

A semiconductor device and a method of fabricating the same, the semiconductor device includes a plurality of fin shaped structures, a trench, a spacing layer and a dummy gate structure. The fin shaped structures are disposed on a substrate. The trench is disposed between the fin shaped structures. The spacing layer is disposed on sidewalls of the trench, wherein the spacing layer has a top surface lower than a top surface of the fin shaped structures. The dummy gate structure is disposed on the fin shaped structures and across the trench.

Claims

1. A method of forming a semiconductor device, comprising:

providing a plurality of mandrels on a substrate, each of the mandrels spaced from each other on a planar surface of the substrate;

removing a portion of the mandrels and a portion of the substrate to form a trench across the mandrels, the trench having a bottom surface lower than the planar surface;

forming a plurality of spacers not sealing the whole trench formed on the planar surface of the substrate, the spacers only covering sidewalls of the mandrels and the trench;

after completely removing the mandrels, using the spacers as a mask to form a plurality of fin shaped structures on the substrate and a plurality of shallow trenches surrounding the fin shaped structures; and

removing a portion of the spacers to form a spacing layer on the sidewalls of the trench, wherein the spacing layer has a top surface being lower than a top surface of the fin shaped structures.

2. The method of forming a semiconductor device of claim 1, further comprising:

forming an insulating layer in the trench, wherein the insulating layer covers on the spacing layer.

3. The method of forming a semiconductor device of claim 1, further comprising:

forming a liner on the sidewalls of the trench and sidewalls of the shallow trench.

4. The method of forming a semiconductor device of claim 3, wherein the liner is formed between the insulating layer and the substrate in the trench.

5. The method of forming a semiconductor device of claim 3, wherein the liner comprises a shoulder portion in the trench.

6. The method of forming a semiconductor device of claim 1, wherein the sidewalls of the trench are tipped, and the spacing layer is also formed on a bottom surface of the trench.

7. The method of forming a semiconductor device of claim 1, further comprising:

forming a dummy gate structure across the trench, wherein a portion of the dummy gate structure is formed in the trench.

8. A method of forming a semiconductor device, comprising:

providing a plurality of mandrels on a substrate;

removing a portion of the mandrels and a portion of the substrate to form a trench across the mandrels;

forming a plurality of spacers not sealing the whole trench formed on sidewalls of the mandrels to surround each of the mandrels respectively, and on sidewalls of the trench;

using the spacers as a mask to form a plurality of fin shaped structures on the substrate and a plurality of shallow trenches surrounding the fin shaped structures; and

completely removing the spacers surrounded each of the mandrels respectively to leave the spacers formed on the sidewalls of the trench to form a spacing layer, wherein the spacing layer has a top surface being lower than a top surface of the fin shaped structures.

9. The method of forming a semiconductor device of claim 8, further comprising:

forming an insulating layer in the trench, wherein the insulating layer covers on the spacing layer.

10. The method of forming a semiconductor device of claim 8, further comprising:

forming a liner on the sidewalls of the trench and sidewalls of the shallow trench.

11. The method of forming a semiconductor device of claim 10, wherein the liner is formed between the insulating layer and the substrate in the trench.

12. The method of forming a semiconductor device of claim 10, wherein the liner comprises a shoulder portion in the trench.

13. The method of forming a semiconductor device of claim 8, wherein the sidewalls of the trench are tipped, and the spacing layer is also formed on a bottom surface of the trench.

14. The method of forming a semiconductor device of claim 8, further comprising:

forming a dummy gate structure across the trench, wherein a portion of the dummy gate structure is formed in the trench.