Etchant and etching process for substrate of a semiconductor device

• US 10,353,147 B2
• Filed: 10/31/2016
• Issued: 07/16/2019
• Est. Priority Date: 01/24/2013
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Lee, Wan-Yu, Kuo, Ying-Hao, Chen, Hai-Ching, Bao, Tien-I
• Primary Examiner(s): Erdem, Fazli
• Application Number:
  US15/339,446
• Publication Number:
  US 20170045685A1
• Time in Patent Office: 988 Days
• Field of Search: 257 98
• CPC Class Codes: C09K 13/02 containing an alkali metal hydroxide
• CPC Class Codes: G02B 2006/12104 Mirror; Reflectors or the like
• CPC Class Codes: G02B 6/1221 made from organic materials
• CPC Class Codes: G02B 6/136 by etching
• CPC Class Codes: G02B 6/42 Coupling light guides with opto-electronic elements
• CPC Class Codes: H01L 21/30604 Chemical etching
• CPC Class Codes: H01L 21/30608 Anisotropic liquid etching H01L21/3063 takes precedence
• CPC Class Codes: H01L 21/3085 characterised by their behaviour during the process, e.g. soluble masks, redeposited masks

Abstract

A system and method for manufacturing semiconductor devices is provided. An embodiment comprises using an etchant to remove a portion of a substrate to form an opening with a 45° angle with a major surface of the substrate. The etchant comprises a base, a surfactant, and an oxidant. The oxidant may be hydrogen peroxide.

Claims

1. A semiconductor device comprising:

an optical bench substrate;

an opening in the optical bench substrate, the opening having a bottom and side surfaces and having an angle of about 45°

from a major surface of the optical bench substrate and having a bottom surface free from etching hillocks at least within a region having a width of about 50 μ

m;

a reflective material covering the bottom and side surfaces of the opening from a first side of the opening to a second side of the opening opposite the first side; and

a waveguide located within the opening.

2. The semiconductor device of claim 1, further comprising a core material located within the opening.

3. The semiconductor device of claim 2, further comprising a cladding material located within the opening.

4. The semiconductor device of claim 3, wherein the core material has a refractive index higher than the cladding material.

5. The semiconductor device of claim 1, further comprising a through via extending from a first side of the optical bench substrate to a second side of the optical bench substrate opposite the first side.

20. The semiconductor device of claim 1, further comprising a through via extending through the optical bench substrate.

6. A semiconductor device comprising:

an optical bench substrate;

an opening for a reflective material in the optical bench substrate, the opening having a sidewall with an angle of about 45°

from a major surface of the optical bench substrate;

an etchant within the opening, the etchant comprising;

a base at a concentration of between about 25%-wt and about 35%-wt;

a surfactant at a concentration of between about 0.01%-wt and about 0.4%-wt; and

an oxidant at a concentration of between about 0.1%-wt and about 0.2%-wt.

7. The semiconductor device of claim 6, wherein the oxidant is H₂O₂.

8. The semiconductor device of claim 6, wherein the oxidant is ozone.

9. The semiconductor device of claim 6, wherein the oxidant is KMnO₄.

10. The semiconductor device of claim 6, wherein the base comprises KOH and the oxidant comprises H₂O₂.

11. The semiconductor device of claim 6, wherein the surfactant comprises a sulfonate base.

12. A semiconductor device comprising:

a semiconductor substrate; and

an opening in the semiconductor substrate;

an etchant within the opening, the etchant comprising;

a base for removing material from a waveguide substrate covered with a patterned hardmask, the base having a concentration of between 25%-wt and about 35%-wt;

a surfactant for modifying an angle of etching to about 45°

from a major surface of the waveguide substrate, the surfactant reactable on the waveguide substrate to form an oil by-product, the surfactant having a concentration of between about 0.01%-wt and about 0.4%-wt; and

an oxidant for oxidizing the waveguide substrate beneath the oil by-product, the oxidant having a concentration of between about 0.1%-wt and about 0.2%-wt.

13. The semiconductor device of claim 12, wherein the oxidant is H₂O₂.

14. The semiconductor device of claim 12, wherein the oxidant is ozone.

15. The semiconductor device of claim 12, wherein the oxidant is KMnO₄.

16. The semiconductor device of claim 12, wherein the base comprises KOH and the oxidant comprises H₂O₂.

17. The semiconductor device of claim 12, wherein the base comprises KOH and the oxidant comprises H₂O₂.

18. The semiconductor device of claim 17, wherein the surfactant comprises a sulfonate base.

19. The semiconductor device of claim 17, wherein the surfactant comprises alkyl polysaccharide.