Structure and method for planar lateral oxidation in passive devices

• US 6,548,908 B2
• Filed: 12/27/1999
• Issued: 04/15/2003
• Est. Priority Date: 12/27/1999
• Status: Expired due to Term

• Current Assignee: Majandro LLC (IP Edge LLC)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Floyd, Philip D., Chua, Christopher L., Sun, Decai, Paoli, Thomas L.
• Primary Examiner(s): Cao, Pat X.
• Assistant Examiner(s): Doan, Theresa T.
• Application Number:
  US09/473,108
• Publication Number:
  US 20020084525A1
• Time in Patent Office: 1,205 Days
• Field of Search: 257/773, 257/12, 257/13, 257/35, 372/96, 372/44-46, 372/50, 372/43, 372/47, 372/48, 372/49
• US Class Current: 257/773
• CPC Class Codes: G02B 2006/12102 Lens
• CPC Class Codes: G02B 2006/12104 Mirror; Reflectors or the like
• CPC Class Codes: G02B 2006/12119 Bend
• CPC Class Codes: G02B 2006/12121 Laser
• CPC Class Codes: G02B 2006/12142 Modulator
• CPC Class Codes: G02B 2006/1215 Splitter
• CPC Class Codes: G02B 2006/12176 Etching
• CPC Class Codes: G02B 6/132 by deposition of thin films
• CPC Class Codes: G02B 6/136 by etching
• CPC Class Codes: H01S 5/18313 by oxidizing at least one of the DBR layers
• CPC Class Codes: H01S 5/18338 Non-circular shape of the structure
• CPC Class Codes: H01S 5/18388 Lenses
• CPC Class Codes: H01S 5/2215 using native oxidation of semiconductor layers

Abstract

A passive semiconductor device structure is made using planar lateral oxidation to define a buried oxidized semiconductor structure such as a passive waveguide, microlens or DBR mirror stack.

Claims

1. A passive semiconductor structure comprising:

a substrate;

a plurality of semiconductor layers formed on said substrate wherein one of said plurality of semiconductor layers is a top layer and at least one of said plurality of semiconductor layers comprises an oxidizable material; and

a plurality of holes extending from said top layer to penetrate into said at least one of said plurality of semiconductor layers that comprises an oxidizable material, the plurality of holes used to form an oxidized lateral surface, the oxidized lateral surface to serve as a wall of a waveguide.

2. The structure of claim 1 wherein at least one hole in said plurality of holes has a triangular cross-section.

3. The semiconductor structure of claim 1 wherein at least one hole in the plurality of holes includes a planar lateral surface.

4. The semiconductor structure of claim 3 wherein at least one hole in the plurality of holes forms a rectangular cross section.

5. The structure of claim 1 further comprising:

a second plurality of holes extending from said top layer to penetrate into said at least one of said plurality of semiconductor layers that comprises an oxidizable material, the second plurality of holes used to form a second oxidized lateral surface, the second oxidized lateral surface forming a second wall of the waveguide.

6. The structure of claim 5 wherein the second wall of the waveguide is oriented parallel to the first wall of the waveguide.

7. The structure of claim 6 wherein the unoxidized region separating the second wall and the first wall is less than approximately 2 micrometers.

8. The structure of claim 1 wherein the wall of the waveguide is formed by a merging of a plurality of oxidation regions, each oxidation region formed from a hole in the plurality of holes.

9. The passive semiconductor structure of claim 1 wherein the plurality of holes further comprises:

at least three holes, the three holes arranged in an approximate line, the oxidizable material oxidized from the at least three holes to form an approximation of an oxidized line to define a non-oxidized continuous stripe region bordered by the oxidized line.

10. The passive semiconductor structure of claim 1 wherein the plurality of holes further comprises:

at least five holes, the at least five holes to define a non-oxidized continuous region bordered by an oxidized region generated by the at least five holes.

11. The passive semiconductor structure of claim 1 wherein the plurality of holes further comprises:

at least five holes, the five holes arranged in an approximate line, the oxidizable material oxidized from the at least five holes to form a continuous oxidized stripe, the continuous oxidized stripe to border a non-oxidized continuous stripe region.

12. A method for making a passive semiconductor structure comprising:

providing a substrate;

forming a plurality of semiconductor layers on said substrate wherein one of said plurality of semiconductor layers is a top layer and at least one of said plurality of semiconductor layers comprises an oxidizable material;

forming a plurality of holes extending from said top layer to penetrate into said at least one of said plurality of semiconductor layers that comprises an oxidizable material; and

,

laterally oxidizing a portion of said oxidizable material from said plurality of holes to form a wall of a waveguide.

13. The method of claim 12 wherein the oxidizing of the lateral surface of said at least one hole further comprises the operation of:

exposing the plurality of holes to saturated water vapor.

14. The method of claim 12 wherein the plurality of holes includes at least three holes formed in an approximate line, the lateral oxidation to form an approximately linear wall of a waveguide that defines a non-oxidized continuous stripe region bordered by the approximately linear wall.

15. The method of claim 12 wherein the plurality of holes includes at least five holes formed in an approximate line, the lateral oxidation to form a wall of a waveguide that defines a non-oxidized continuous stripe region bordered by the wall of the waveguide.

16. The method of claim 12 wherein the plurality of holes includes at least five holes, the lateral oxidation from the at least five holes to form a wall of a waveguide that defines a non-oxidized continuous stripe region bordered by the wall of the waveguide.

17. A method of forming a waveguide comprising the operations of:

providing a substrate;

forming a plurality of semiconductor layers on said substrate wherein one of said plurality of semiconductor layers is a top layer and at least one of said plurality of semiconductor layers comprises an oxidizable material;

forming a plurality of holes extending from said top layer to penetrate into said at least one of said plurality of semiconductor layers that comprises an oxidizable material; and

,

laterally oxidizing a portion of said oxidizable material from said plurality of holes to form a wall of the waveguide.

18. The method of claim 17 wherein the wall of the waveguide is formed from the merging of oxidation regions surrounding each hole in the plurality of holes.