METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE HAVING OPTICAL DEVICES

• US 20110136318A1
• Filed: 05/19/2010
• Published: 06/09/2011
• Est. Priority Date: 12/09/2009
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Kim, Gyungock, Hong, Jun Taek, KIM, In Gyoo, Park, Dae Seo
• Granted Patent: US 8,394,705 B2
• Time in Patent Office: Days
• US Class Current: 438/425
• CPC Class Codes: G02B 6/132 by deposition of thin films
• CPC Class Codes: G02B 6/136 by etching
• CPC Class Codes: G02F 1/212 Mach-Zehnder type
• CPC Class Codes: G02F 1/2257 the optical waveguides being made of semiconducting material
• CPC Class Codes: G02F 2203/15 involving resonance effects, e.g. resonantly enhanced interaction
• CPC Class Codes: H01L 27/1203 the substrate comprising an insulating body on a semiconductor body, e.g. SOI three-dimensional layout H01L27/0688

Abstract

Provided is a method of manufacturing a semiconductor device. According to the method, a first buried oxide layer is formed in the semiconductor substrate in a first region, such that a first semiconductor layer is defined on the first buried oxide layer. An active portion is defined by forming a trench in the semiconductor substrate in a second region. A capping semiconductor pattern is formed on a top surface and an upper portion of a sidewall of the active portion. An oxide layer is formed by oxidizing the capping semiconductor pattern and an exposed lower portion of the sidewall of the active portion, such that the oxide layer surrounds a non-oxidized portion of the active portion. The non-oxidized portion of the active portion is a core and one end of the core is connected to a first optical device formed at the first semiconductor.

Claims

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

providing a semiconductor substrate having a first region and a second region;

forming a first buried oxide layer in the semiconductor substrate in the first region, wherein a first semiconductor layer is defined on the first buried oxide layer in the first region;

defining an active portion by forming a trench in the semiconductor substrate in the second region;

forming a capping semiconductor pattern on a top surface of the active portion and an upper portion of a sidewall of the active portion and exposing a lower portion of the sidewall of the active portion;

forming an oxide layer by oxidizing the capping semiconductor pattern and the lower portion of the sidewall of the active portion through an oxidizing process, wherein the oxide layer surrounds a non-oxidized portion of the active portion; and

forming a first optical device at the semiconductor layer, wherein the non-oxidized portion of the active portion is a core through which optical signals passes and a first end of the core is connected to the first optical device.

2. The method of claim 1, wherein the capping semiconductor pattern is fully oxidized by the oxidizing process.

3. The method of claim 1, wherein the forming of the capping semiconductor pattern comprises:

forming a sacrificing pattern filling the trench;

exposing the upper portion of the sidewall of the active portion by recessing the sacrificing pattern;

conformally forming the capping semiconductor layer on the substrate;

removing the capping semiconductor layer on the recessed sacrificing pattern to expose the recessed sacrificing pattern and to form the capping semiconductor pattern; and

removing the exposed sacrificing pattern to expose the lower portion of the sidewall of the active portion.

4. The method of claim 3, wherein the capping semiconductor pattern extends to cover a top surface of the first semiconductor layer;

and

a portion of the capping semiconductor pattern on the first semiconductor layer is oxidized by the oxidizing process, so that the oxide layer further formed on the first semiconductor layer.

5. The method of claim 4, further comprising:

before forming of the first optical device, removing the oxide layer on the first semiconductor layer.

6. The method of claim 5, wherein the removing of the oxide layer on the first semiconductor layer comprises planarizing the oxide layer until the first semiconductor layer and a top surface of the core are exposed.

7. The method of claim 3, further comprising:

before the forming of the capping semiconductor layer, forming a buffer layer on the exposed upper portion of the sidewall of the active portion and the top surface of the active portion.

8. The method of claim 7, wherein the buffer layer is further formed on the first semiconductor layer.

9. The method of claim 1, wherein the semiconductor substrate further comprises a third region spaced apart from the first and second regions,

the method further comprising:

forming a second buried oxide layer in the semiconductor substrate in the third region, wherein a second semiconductor layer is defined on the second buried oxide layer in the third region; and

forming a second optical device at the second semiconductor layer, wherein the second optical device is connected to a second end of the core.

10. The method of claim 9, wherein the first and second optical devices are formed after the core and the oxide layer by the oxidizing process are formed.

11. The method of claim 9, wherein the first and second buried oxide layers are simultaneously formed.

12. The method of claim 9, wherein the first and second buried oxide layer is formed through a separation by implanted oxygen (SIMOX) process.

13. The method of claim 1, wherein the capping semiconductor pattern is formed of a same material as the semiconductor substrate.

14. The method of claim 1, wherein the capping semiconductor pattern is in a polycrystal state and the semiconductor substrate is in a single-crystal state.

15. The method of claim 1, wherein the semiconductor substrate is a bulk silicon substrate, the capping semiconductor pattern is formed of polysilicon, and the oxide layer by the oxidizing process is a silicon oxide layer.