Method for patterning a sequence of layers and semiconductor laser device

Patent metadata

Field	Value
Publication number	US-10312664-B2
Application number	US-201515517144-A
Country	US
Kind code	B2
Filing date	Sep 21, 2015
Priority date	Oct 20, 2014
Publication date	Jun 4, 2019
Grant date	Jun 4, 2019

Abstract

A method for patterning a sequence of layers and a semiconductor laser device are disclosed. In an embodiment the method creates at least one trench in the sequence of layers by two plasma etching methods. The semiconductor laser device comprises a sequence of layers including a semiconductor material and two trenches in the sequence of layers. The trenches laterally delimit a ridge waveguide. Each of the trenches is delimited on the side facing away from the ridge waveguide by a region of the sequence of layers.

First claim

The invention claimed is:

1. A method for patterning a sequence of layers comprising:
providing the sequence of layers, wherein the sequence of layers comprises a first layer and a second layer, which differ from one another in terms of their material composition;
applying a first mask on a top surface of the first layer facing away from the second layer;
partially removing the first layer in an area of the sequence of layers not covered by the first mask and partially exposing the second layer by a first plasma etching method; and
at least partially removing the exposed second layer by a second plasma etching method,
wherein the first layer is removed faster or greater by the first plasma etching method with a diminishing distance in a direction lateral to the first mask,
wherein the first layer is removed at a lower etch rate than the second layer during the second plasma etching method,
wherein at least one trench is created in the sequence of layers, wherein the at least one trench extends completely through the first layer and only partly into the second layer, and wherein a bottom surface of the at least one trench is formed by a part of the second layer.

2. The method according to claim 1 , wherein the first layer and the second layer are removed at etch rates that are very similar but not necessarily the same during the first plasma etching method.

3. The method according to claim 1 , wherein the at least one trench directly borders the first mask laterally.

4. The method according to claim 1 , wherein a lateral extent of the at least one trench perpendicular or transverse to a lateral surface of the first mask facing the trench is small compared with a lateral extent of an opening in the first mask.

5. The method according to claim 1 , wherein a lateral extent of the at least one trench is less than 800 nm.

6. The method according to claim 1 , wherein the sequence of layers comprises a third layer, wherein the third layer is arranged on a side of the second layer facing away from the first layer, and wherein the second layer and the third layer differ from one another in terms of their material composition.

7. The method according to claim 6 , wherein the at least one trench extends directly at or into, or through the third layer.

8. The method according to claim 1 , wherein the sequence of layers is formed using semiconductor material, wherein the first mask covers a ridge waveguide, and wherein, in each case, one of the trenches is created on opposite sides of the first mask in such a way that the trenches laterally delimit the ridge waveguide.

9. The method according to claim 8 , wherein each of the trenches is delimited on its side facing away from the ridge waveguide by an area of the sequence of layers which, measured from a lowest point of the trench, has a maximum height which corresponds to between at least 90% and at most 99% of a maximum height of the ridge waveguide.

10. A method for patterning a sequence of layers comprising:
providing the sequence of layers, wherein the sequence of layers comprises a first layer and a second layer, which differ from one another in terms of their material composition;
applying a first mask on a top surface of the first layer facing away from the second layer;
partially removing the first layer in an area of the sequence of layers not covered by the first mask and partially exposing the second layer by a first plasma etching method;
at least partially removing the exposed second layer by a second plasma etching method; and
after performing the first plasma etching method and before performing the second plasma etching method, applying a second mask on the top surface of the first layer facing away from the second layer, wherein a position of the second mask is at most partially congruent with a position of the first mask, wherein the first plasma etching method is performed again,
wherein the first layer is removed faster or greater by the first plasma etching method with a diminishing distance in a direction lateral to the first mask,
wherein the first layer is removed at a lower etch rate than the second layer during the second plasma etching method,
wherein at least one trench is created in the sequence of layers, and wherein the at least one trench extends completely through the first layer and at least partially through the second layer.

11. The method according to claim 10 , wherein the positions of the first mask and of the second mask partially overlap.

12. The method according to claim 10 , wherein the first mask is removed before the second mask is applied.

Assignees

• Osram Opto Semiconductors Gmbh

Inventors

• Rumbolz Christian
• Gerhard Sven

Classifications

• H10W10/0145

  of trenches having shapes other than rectangular or V-shape (H10W10/0143 takes precedence) · CPC title

• H10W10/17

  formed using trench refilling with dielectric materials, e.g. shallow trench isolations · CPC title

• H10P50/242

  of Group IV materials · CPC title

• H01S5/0224

  Electricity · mapped topic

• H01S5/2081 Primary

  using special etching techniques · CPC title