Semiconductor device and method of making a semiconductor device

Patent metadata

Field	Value
Publication number	US-11569357-B2
Application number	US-202117319380-A
Country	US
Kind code	B2
Filing date	May 13, 2021
Priority date	May 13, 2021
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

A semiconductor device and a method of making a semiconductor device. The device includes an emitter. The device also includes a collector. The device further includes a base stack. The base is located between the emitter and the collector. The base stack includes an intrinsic base region. The device further includes a base electrode. The base electrode comprises a silicide. The silicide of the base electrode may be in direct contact with the base stack. The device may be a heterojunction bipolar transistor.

First claim

The invention claimed is:

1. A method of making a semiconductor device, the method comprising:
forming a collector;
depositing a semiconductor layer;
forming a base stack of the semiconductor device, wherein the base stack comprises an intrinsic base region, and wherein the semiconductor layer is in direct contact with the base stack;
forming an emitter of the semiconductor device, wherein the base stack is located between the emitter and the collector;
depositing a metallic portion on the semiconductor layer;
performing a silicidation process to form a silicide from the semiconductor layer and the metallic portion, wherein the silicide grows toward the base stack during said silicidation process to form a base electrode of the semiconductor device; and
forming the device on a major surface of a semiconductor die, wherein a plane of contact between the silicide of the base electrode and the base stack is oriented at a non-zero, non-orthogonal angle with respect to the major surface.

2. The method of claim 1 , comprising depositing the metallic portion laterally separated from the base stack, wherein said silicidation process causes the silicide to grow towards and come into direct contact with the base stack.

3. The method of claim 2 , wherein said silicidation process causes the silicide to grow towards and come into direct contact with the intrinsic base region of the base stack.

4. The method of claim 1 , wherein said growth of the silicide towards the base stack is driven by starvation of semiconductor material in parts of the semiconductor layer distal the base stack.

5. The method of claim 1 , wherein the silicidation process comprises:
a first thermal annealing process to produce a first phase material from the semiconductor layer and the metallic portion; and
a second thermal annealing process to produce said silicide from the first phase material.

6. The method of claim 5 , comprising an etch process after the first thermal annealing process to remove unreacted parts of the metallic portion before performing the second thermal annealing process.

7. The method of claim 1 , wherein the silicidation process comprises a first thermal annealing process to produce said silicide from the semiconductor layer and the metallic portion.

8. The method of claim 1 , comprising depositing one or more layers of dielectric prior to depositing said semiconductor layer in direct contact with the base stack, to electrically isolate the base electrode from the collector.

9. The method of claim 1 , wherein said silicidation process also forms silicide on the emitter, wherein the silicide of the emitter is a same type of silicide as the silicide of the base electrode.

10. The method of claim 1 , wherein the semiconductor layer comprises silicon and wherein the metallic portion and the silicide comprise one of the group consisting of:
the metallic portion comprises Co and the silicide comprises CoSi 2 ,
the metallic portion comprises Ni and the silicide comprises NiSi, and
the metallic portion comprises NiPt and the silicide comprises NiPtSi.

11. A method of making a semiconductor device, the method comprising:
forming a collector;
depositing a semiconductor layer;
forming a base stack of the semiconductor device, wherein the base stack comprises an intrinsic base region, and wherein the semiconductor layer is in direct contact with the base stack;
forming an emitter of the semiconductor device, wherein the base stack is located between the emitter and the collector;
depositing a metallic portion on the semiconductor layer;
performing a silicidation process to form a silicide from the semiconductor layer and the metallic portion, wherein the silicide grows toward the base stack during said silicidation process to form a base electrode of the semiconductor device; and
depositing the metallic portion laterally separated from the base stack, wherein said silicidation process causes the silicide to grow towards and come into direct contact with the base stack.

12. The method of claim 11 , wherein said silicidation process causes the silicide to grow towards and come into direct contact with the intrinsic base region of the base stack.

Assignees

• Nxp Usa Inc

Inventors

• Kirchgessner James Albert
• John Jay Paul
• Kwan Steven

Classifications

• H01L29/7375

  Electricity · mapped topic

• H01L29/42304 Primary

  Electricity · mapped topic

• H01L29/401

  Electricity · mapped topic

• H01L29/456

  Electricity · mapped topic

• H01L29/66242

  Electricity · mapped topic