Photodetector with built-in circuit and method for producing the same

• US 20020030206A1
• Filed: 08/06/2001
• Published: 03/14/2002
• Est. Priority Date: 09/08/2000
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Takimoto, Takahiro, Kubo, Masaru, Tani, Zenpei, Kasamatsu, Toshimitsu, Okubo, Isamu
• Granted Patent: US 6,707,081 B2
• Time in Patent Office: Days
• US Class Current: 257/292
• CPC Class Codes: H01L 27/1443 with at least one potential jump or surface barrier

Abstract

A photodetector with a built-in circuit includes a semiconductor substrate, an integrated circuit provided on the semiconductor substrate, and a photodiode provided on the semiconductor substrate. The integrated circuit includes a SiGe layer provided on at least a portion of the integrated circuit.

Claims

1. A photodetector with a built-in circuit, comprising:

a semiconductor substrate;

an integrated circuit provided on the semiconductor substrate; and

a photodiode provided on the semiconductor substrate,

wherein the integrated circuit includes a SiGe layer provided on at least a portion of the integrated circuit.

2. A photodetector with a built-in circuit according to claim 1, wherein the photodiode includes a homojunction of Si.

3. A photodetector with a built-in circuit according to claim 1, wherein the photodiode includes a plurality of split photodiodes.

4. A photodetector with a built-in circuit according to claim 1, wherein the photodiode includes an antireflection film provided on the semiconductor substrate and

the antireflection film includes a silicon thermal oxide film.

5. A photodetector with a built-in circuit according to claim 4, wherein the antireflection film further includes a silicon nitride film.

6. A photodetector with a built-in circuit according to claim 4, wherein a thickness of the silicon thermal oxide film is between about 10 nm or more and about 40 nm or less.

7. A photodetector with a built-in circuit according to claim 1, wherein the semiconductor substrate includes a first conductivity-type semiconductor having a high resistivity.

8. A photodetector with a built-in circuit according to claim 1, wherein the semiconductor substrate includes:

a first conductivity-type semiconductor substrate having a low resistivity; and

a first conductivity-type epitaxial layer provided on the first conductivity-type semiconductor substrate which has a resistivity higher than that of at least the first conductivity-type semiconductor substrate.

9. A photodetector with a built-in circuit according to claim 1, wherein the semiconductor substrate includes:

a first conductivity-type semiconductor substrate having a low resistivity;

a first conductivity-type semiconductor layer provided on the first conductivity-type semiconductor substrate which has a resistivity lower than that of at least the first conductivity-type semiconductor substrate; and

a first conductivity-type epitaxial layer provided on the first conductivity-type semiconductor layer which has a resistivity higher than that of at least the first conductivity-type semiconductor substrate.

10. A method for producing a photodetector with a built-in circuit, wherein the photodetector with a built-in circuit includes:

a semiconductor substrate;

an integrated circuit formed on the semiconductor substrate; and

a photodiode provided on the semiconductor substrate,

wherein the integrated circuit includes a SiGe layer formed on at least a portion of the integrated circuit,

the method includes the steps of;

a) forming the photodiode on the semiconductor substrate; and

b) forming the SiGe layer after the photodiode is formed.

11. A method for producing a photodetector with a built-in circuit according to claim 10, wherein:

the photodiode includes an antireflection layer provided on the semiconductor substrate;

step a) includes the step of

c) forming the antireflection layer on the semiconductor substrate;

step c) includes the step of forming a silicon thermal oxide film on the semiconductor substrate;

step b) includes the steps of;

etching the silicon thermal oxide film formed on step c); and

forming the SiGe layer by low temperature MBE.

12. A method for producing a photodetector with a built-in circuit according to claim 11, wherein step c) includes the steps of forming a silicon nitride film on the silicon thermal oxide film and simultaneously forming a silicon nitride film used as a silicon nitride film capacitance portion in the integrated circuit.

13. A method for producing a photodetector with a built-in circuit according to claim 12, wherein step c) includes the step of forming a silicon oxide film on the silicon nitride film so as to protect the silicon nitride film.

14. A method for producing a photodetector with a built-in circuit according to claim 13, wherein step c) includes the step of:

d) etching the silicon oxide film after all dry-etching processes are completed.

15. A method for producing a photodetector with a built-in circuit according to claim 14, further comprising the step of:

(e) forming a cover insulation film to pattern the cover insulation film by dry-etching, wherein step d) is executed after the execution of step e).

16. A method for producing a photodetector with a built-in circuit according to claim 15, wherein step d) includes the step of etching the silicon oxide film while the cover insulation film functions as a protection film.