Method of making semiconductor device having a schottky gate electrode

• US 5,712,175 A
• Filed: 09/06/1995
• Issued: 01/27/1998
• Est. Priority Date: 09/12/1994
• Status: Expired due to Fees

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Yoshida, Kazuhiro
• Primary Examiner(s): CHAUDHARI, CHANDRA P
• Application Number:
  US08/524,208
• Time in Patent Office: 874 Days
• Field of Search: 437/39, 437/405 H, 437/415 H, 437/175, 148/DIG. 139, 148/DIG. 140
• US Class Current: 438/167
• CPC Class Codes: H01L 21/0272 for lift-off processes
• CPC Class Codes: H01L 21/28581 Deposition of Schottky electrodes
• CPC Class Codes: H01L 21/28587 characterised by the sectional shape, e.g. T, inverted T
• CPC Class Codes: H01L 29/66863 Lateral single gate transistors

Abstract

A method of manufacturing a semiconductor device using an inexpensive apparatus such as an i-line stepper, with a high throughput and a high yield at a low cost. Exemplary embodiments of the method include a step for forming a first layer of an insulative film on a semiconductor substrate, a step of forming a second layer of a resist for gate patterning on the first layer of the insulative film, a step of forming a pattern having a desired gate length on the second layer of the resist, a step of transcribing a gate pattern in the first layer of the insulative film by an anisotropic etching, and a step of patterning a cap of a mushroom-type gate electrode or an eave of a Γ-type electrode by using a third layer of a resist.

Claims

1. A method of making a semiconductor device having a Schottky gate electrode on a semiconductor substrate comprising the steps of:

forming a first layer of an insulative film on the semiconductor substrate;

forming a second layer of a resist for a gate patterning on the first layer of the insulative film;

forming a gate pattern on the second layer of the resist;

transcribing the gate pattern in the first layer of the insulative film by anisotropic etching; and

after said transcribing step, forming a third layer of a resist for forming a mushroom-type gate electrode and patterning a cap portion of the mushroom-type gate electrode.

2. The method of making a semiconductor device according to claim 1, wherein the step of forming a first layer further comprises the step of:

forming a first layer of an insulative film with one or more materials selected from the group consisting of a silicon nitride film, a silicon oxide film, and a resist film.

3. A method of making a semiconductor device according to claim 1, further comprising the step of:

forming a source electrode and a drain electrode on the semiconductor substrate, said first layer of insulative film being formed with a thickness approximately equal to a thickness of at least one of said source electrode and said drain electrode.

4. A method of making a semiconductor device according to claim 3, wherein said first layer of insulative film is formed between said source electrode and said drain electrode.

5. A method of making a semiconductor device according to claim 1, wherein said step of forming a gate pattern further includes the step of:

forming said gate pattern with a predetermined gate length on the second layer of the resist.

6. A method of making a semiconductor device according to claim 1, further comprising the step of:

forming the mushroom-type gate electrode by vapor deposition.

7. A method of making a semiconductor device according to claim 1, wherein said step of forming a first layer further includes the steps of:

coating said semiconductor substrate with said insulative film; and

etching said insulative film.

8. A method of making a semiconductor device according to claim 1, wherein said step of forming a second layer further includes a step of:

forming said second layer with a thickness based on exposure sensitivity of an i-line stepper.

9. A method of making a semiconductor device according to claim 1, further comprising the step of:

rounding corners of the gate pattern transcribed in said first layer of the insulative film using a resist reflow.

10. The method of making a semiconductor device according to claim 1, further comprising the steps of:

forming said mushroom-type gate electrode with a gate metal deposited by evaporation.

11. A method of making a semiconductor device having a Schottky gate electrode on a semiconductor substrate comprising the steps of:

forming a first layer of an insulative film on the semiconductor substrate;

forming a second layer of a resist for a gate patterning on the first layer of the insulative film;

forming a gate pattern on the second layer of the resist;

transcribing the gate pattern in the first layer of the insulative film by an anisotropic etching;

after said transcribing step, forming a third layer of a resist for forming a Γ

-type gate electrode with a post proximate to a side of a source electrode and with an eave proximate to a side of a drain electrode; and

patterning the eave proximate to the side of the drain electrode on the third layer of the resist.

12. The method of making a semiconductor device according to claim 11, further comprising a step of:

forming said first layer of said insulative film with a thickness approximately equal to a thickness of at least one of said source electrode and said drain electrode.

13. A method of making a semiconductor device according to claim 12, wherein said first layer of insulative film is formed between said source electrode and said drain electrode.

14. A method of making a semiconductor device according to claim 11, wherein said step of forming a gate pattern further includes the step of:

forming said gate pattern with a predetermined gate length on the second layer of the resist.

15. A method of making a semiconductor device according to claim 11, further comprising the step of:

forming the Γ

-type gate electrode by vapor deposition.

16. A method of making a semiconductor device according to claim 11, wherein said step of forming a first layer further includes the steps of:

coating said semiconductor substrate with said insulative film; and

etching said insulative film.

17. The method of making a semiconductor device according to claim 11, wherein the step of forming a first layer further comprises the step of:

forming a first layer of an insulative film with one or more materials selected from the group consisting of a silicon nitride film, a silicon oxide film, and a resist film.

18. A method of making a semiconductor device according to claim 11, wherein said step of forming a second layer further includes a step of:

forming said second layer with a thickness based on exposure sensitivity of an i-line stepper.

19. The method of making a semiconductor device according to claim 11, further comprising the step of:

forming said eave by at least one of a chlorobenzene treatment and a multi-layer resist method.

20. A method of making a semiconductor device according to claim 11, further comprising the step of:

forming said Γ

-type gate electrode with a gate metal deposited by evaporation.