Method of manufacturing recognition sensor

• US 7,360,293 B2
• Filed: 04/07/2005
• Issued: 04/22/2008
• Est. Priority Date: 01/23/2001
• Status: Expired due to Term

• Current Assignee: Nippon Telegraph and Telephone Corporation
• Original Assignee: Nippon Telegraph and Telephone Corporation
• Inventors: Shigematsu, Satoshi, Morimura, Hiroki, Kyuragi, Hakaru, Ishii, Hiromu, Sato, Norio, Machida, Katsuyuki, Shimamura, Toshishige
• Primary Examiner(s): Arbes; Carl J.
• Application Number:
  US11/102,269
• Publication Number:
  US 20050214960A1
• Time in Patent Office: 1,111 Days
• Field of Search: 295/921, 295/95, 298/25, 298/32
• US Class Current: 29/595
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49007 Indicating transducer
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.

Abstract

A method of manufacturing a surface shape recognition sensor. A sacrificial film is formed on an interlevel dielectric to cover a lower electrode while keeping an upper portion of a support electrode exposed. An upper electrode is formed on the sacrificial film and support electrode. The sacrificial film is selectively removed and a protective film is formed on the upper electrode. A photosensitive resin film having photosensitivity is formed on the protective film. A plurality of projections are formed in a region of the protective film above a capacitive detection element. In this manner a plurality of capacitive detection elements each having the lower electrode and upper electrode are formed.

Claims

1. A method of manufacturing a surface shape recognition sensor, comprising the steps of:

forming an interlevel dielectric on a semiconductor substrate;

forming a first metal film on the interlevel dielectric;

forming a first mask pattern having an opening portion in a predetermined region on the first metal film;

forming a first metal pattern on a surface of the first metal film exposed to a bottom portion of the opening portion of the first mask pattern by plating;

after the first mask pattern is removed, forming a second mask pattern having an opening portion laid out around the first metal pattern on the first metal film and first metal pattern;

forming a second metal pattern thicker than the first metal pattern on the surface of the first metal film exposed to a bottom portion of the opening portion of the second mask pattern by plating;

after the second mask pattern is removed, etching and removing the first metal film using the first and second metal patterns as a mask to form a lower electrode formed from the first metal film and first metal pattern and a support electrode formed from the first metal film and second metal pattern;

forming a sacrificial film on the interlevel dielectric to cover the lower electrode while keeping an upper portion of the support electrode exposed;

forming an upper electrode having a plurality of opening portions on the sacrificial film and support electrode;

after the upper electrode is formed, selectively removing only the sacrificial film through the opening portions;

after the sacrificial film is removed, forming a protective film on the upper electrode; and

forming a plurality of projections in a region of the protective film above a capacitive detection element, wherein a plurality of capacitive detection elements each having the lower electrode and upper electrode are formed, and the protective film is formed on the upper electrode by transfer.

2. A method according to claim 1, wherein in the protective film transfer step, STP is used as a transfer method.

3. A method according to claim 1, wherein

the lower electrode formation step comprises the steps of forming the first metal film on the semiconductor substrate, forming a first patterned resist on the first metal film, forming the lower electrode in an opening portion of the first resist, and removing the first resist,

the support electrode formation step comprises the steps of forming a second patterned resist on the first metal film, forming the support electrode in an opening portion of the second resist, removing the second resist, and etching the first metal film using the lower electrode and support electrode as a mask,

the upper electrode formation step comprises the steps of forming the sacrificial film on the lower electrode and support electrode, removing the sacrificial film on the support electrode to expose the support electrode, forming a second metal film on the support electrode and sacrificial film, forming a third patterned resist on the second metal film, forming the upper electrode in an opening portion of the third resist, removing the third resist, etching the second metal film using the upper electrode as a mask, and removing the sacrificial film,

the protective film transfer step comprises the step of transferring the protective film onto the upper electrode by STP,

the photosensitive resin film formation step comprises the step of applying the photosensitive resin film onto the protective film, and

the step of fabricating the photosensitive resin film into the projections comprises the steps of exposing part of the photosensitive resin film and executing development after exposure.

4. A method according to claim 1, wherein the sacrificial film is essentially formed from a polyimide resin.

5. A method according to claim 1, wherein the sacrificial film is essentially formed from a polybenzoxazole precursor resin.

6. A method according to claim 1, wherein the sacrificial film is removed by heating the sacrificial film and simultaneously exposing the sacrificial film to an ozone ambient.

7. A method according to claim 1, wherein the lower electrode, support electrode, and upper electrode are essentially formed from gold.

8. A method according to claim 1, wherein the upper electrode is formed on the sacrificial film and support electrode while separating the opening portions from a side wall of the support electrode, and after the sacrificial film is removed, a liquid material is applied onto the upper electrode to form a coat, and the coat is hardened to form the protective film on the upper electrode to close the opening portions, and wherein in forming the coat, the coat is laid out on a force acting side of the substrate and hardened.

9. A method according to claim 8, wherein in forming the coat, the coat is laid out on a lower side of the substrate and hardened.

10. A method according to claim 8, wherein

letting t be a thickness of the coat in a region other than the opening portions in forming the coat,

a be a sectional area of the opening portion at a boundary between the opening portion and an external portion of a space formed between the upper electrode and the lower electrode,

b be a peripheral length of a section of the opening portion at a boundary between the space and the opening portion,

c be a volume in the opening portion,

d be the magnitude of surface tension, at the boundary between the space and the opening portion, between an opening portion inner wall and a portion of the coat that has entered the opening portion,

e be a density of the coat, and g be a gravitational acceleration, a relationship given by

(c+a×

t)×

e×

g≦

b×

d

is satisfied.

11. A method according to claim 8, wherein

the upper electrode is formed by plating gold on and around the sacrificial film, and

the coat is formed by applying the liquid material formed from polyimide.

12. A method according to claim 11, wherein

the coat is formed by applying the liquid material formed from polyimide having photosensitivity, and

the protective film is formed in an opening portion region on the upper electrode to close the opening portions by removing a region of the coat other than a peripheral region of the opening portions by photolithography and hardening a remaining portion.

13. A method according to claim 1, wherein before the sacrificial film is formed,

a first dielectric film that is lower than the support electrode and covers the lower electrode is formed on the lower electrode, and

the first dielectric film is selectively removed to form an electrode dielectric film on the lower electrode.

14. A method according to claim 1, wherein after the first metal pattern is formed,

a first dielectric film is formed on the first metal pattern to cover the first metal pattern,

the first mask pattern is removed to form an electrode dielectric film on the first metal pattern, and then,

the second mask pattern is formed.

15. A method according to claim 1, wherein

after the first mask pattern is removed, a first dielectric film is formed on the first metal pattern to cover the first metal pattern,

the first dielectric film is selectively removed to form an electrode dielectric film on the first metal pattern, and

after the electrode dielectric film is formed, the second mask pattern is formed.

16. A method according to claim 1, wherein the step of forming a plurality of projections comprises the steps of:

forming a photosensitive resin film on the protective film; and

forming the plurality of projections by exposing and developing a predetermined pattern on the photosensitive resin film.

17. A method according to claim 1, wherein the step of forming a plurality of projections comprises the steps of:

forming a second metal film on the protective film;

forming a third mask pattern having an opening portion in a predetermined region on the second metal film;

forming a third metal pattern by plating on a surface of the second metal film which is exposed to a bottom of an opening portion of the third mask pattern;

after removing the third mask pattern, etching the second metal film using the third metal pattern as a mask to form the projection formed from the second metal film and the third metal pattern.

18. A method according to claim 8, wherein letting t be a thickness of the coat in a region other than the opening portions in forming the coat,

a be a sectional area of the opening portion at a boundary between the opening portion and an external portion of a space formed between the upper electrode and the lower electrode,

b be a peripheral length of a section of the opening portion at a boundary between the space and the opening portion,

c be a volume in the opening portion,

d be the magnitude of surface tension, at the boundary between the space and the opening portion, between an opening portion inner wall and a portion of the coat that has entered the opening portion, e be a density of the coat, and

g be a gravitational acceleration, a relationship given by

(c+a×

t)×

e×

g≦

b×

d

is satisfied,

and

wherein the upper electrode is formed by plating gold on and around the sacrificial film, and the coat is formed by applying the liquid material formed from polyimide.

19. A method according to claim 18, wherein the coat is formed by applying the liquid material formed from polyimide having photosensitivity, and the protective film is formed in an opening portion region on the upper electrode to close the opening portions by removing a region of the coat other than a peripheral region of the opening portions by photolithography and hardening a remaining portion.

20. A method of manufacturing a surface shape recognition sensor, comprising the steps of:

forming an interlevel dielectric on a semiconductor substrate;

forming a first metal film on the interlevel dielectric;

forming a first mask pattern having an opening portion in a predetermined region on the first metal film;

forming a first metal pattern on a surface of the first metal film exposed to a bottom portion of the opening portion of the first mask pattern by plating;

after the first mask pattern is removed, forming a second mask pattern having an opening portion laid out around the first metal pattern on the first metal film and first metal pattern;

forming a second metal pattern thicker than the first metal pattern on the surface of the first metal film exposed to a bottom portion of the opening portion of the second mask pattern by plating;

after the second mask pattern is removed, etching and removing the first metal film using the first and second metal patterns as a mask to form a lower electrode formed from the first metal film and first metal pattern and a support electrode formed from the first metal film and second metal pattern;

forming a sacrificial film on the interlevel dielectric to cover the lower electrode while keeping an upper portion of the support electrode exposed;

forming an upper electrode having a plurality of opening portions on the sacrificial film and support electrode;

after the upper electrode is formed, selectively removing only the sacrificial film through the opening portions;

after the sacrificial film is removed, forming a photosensitive resin film having photosensitivity on the upper electrode; and

simultaneously forming a protective film that covers the upper electrode and a plurality of projections laid out in a region of the protective film above a capacitive detection element by exposing and developing a predetermined pattern on the photosensitive resin film,

wherein a plurality of capacitive detection elements each having the lower electrode and upper electrode are formed.

21. A method according to claim 20, wherein the photosensitive resin film is formed on the upper electrode by transfer.

22. A method according to claim 21, wherein in the photosensitive resin film transfer step, STP is used as a transfer method.

23. A method according to claim 21, wherein

the lower electrode formation step comprises the steps of forming the first metal film on the semiconductor substrate, forming a first patterned resist on the first metal film, forming the lower electrode in an opening portion of the first resist, and removing the first resist,

the support electrode formation step comprises the steps of forming a second patterned resist on the first metal film, forming the support electrode in an opening portion of the second resist, removing the second resist, and etching the first metal film using the lower electrode and support electrode as a mask,

the upper electrode formation step comprises the steps of forming the sacrificial film on the lower electrode and support electrode, removing the sacrificial film on the support electrode to expose the support electrode, forming a second metal film on the support electrode and sacrificial film, forming a third patterned resist on the second metal film, forming the upper electrode in an opening portion of the third resist, removing the third resist, etching the second metal film using the upper electrode as a mask, and removing the sacrificial film,

the photosensitive resin film transfer step comprises the step of transferring the photosensitive resin film onto the upper electrode by STP, and

the step of forming the protective film and the plurality of projections on the protective film comprises the steps of exposing part of the photosensitive resin film and executing development after exposure.

24. A method of manufacturing a surface shape recognition sensor, comprising the steps of:

forming an interlevel dielectric on a semiconductor substrate;

forming a first metal film on the interlevel dielectric;

forming a first mask pattern having an opening portion in a predetermined region on the first metal film;

forming a first metal pattern on a surface of the first metal film exposed to a bottom portion of the opening portion of the first mask pattern by plating;

after the first mask pattern is removed, forming a second mask pattern having an opening portion laid out around the first metal pattern on the first metal film and first metal pattern;

forming a second metal pattern thicker than the first metal pattern on the surface of the first metal film exposed to a bottom portion of the opening portion of the second mask pattern by plating;

after the second mask pattern is removed, etching and removing the first metal film using the first and second metal patterns as a mask to form a lower electrode formed from the first metal film and first metal pattern and a support electrode formed from the first metal film and second metal pattern;

forming a sacrificial film on the interlevel dielectric to cover the lower electrode while keeping an upper portion of the support electrode exposed;

forming an upper electrode having a plurality of opening portions on the sacrificial film and support electrode;

after the upper electrode is formed, selectively removing only the sacrificial film through the opening portions;

after the sacrificial film is removed, forming a protective film on the upper electrode;

forming a second metal film on the protective film;

forming a third mask pattern having an opening portion in a predetermined region on the second metal film;

forming a third metal pattern on a surface of the second metal film exposed to a bottom portion of the opening portion of the third mask pattern by plating; and

after the third mask pattern is removed, etching and removing the second metal film using the third metal pattern as a mask to form a projection formed from the second metal film and third metal pattern wherein a plurality of capacitive detection elements each having the lower electrode and upper electrode are formed;

wherein in forming the coat, the coat is laid out on a force acting side of the substrate and hardened, and

wherein the protective film is formed on the upper electrode by transfer.

25. A method according to claim 24, wherein in forming the coat, the coat is laid out on a lower side of the substrate and hardened.

26. A method according to claim 24, wherein

letting t be a thickness of the coat in a region other than the opening portions in forming the coat,

a be a sectional area of the opening portion at a boundary between the opening portion and an external portion of a space formed between the upper electrode and the lower electrode,

b be a peripheral length of a section of the opening portion at a boundary between the space and the opening portion,

c be a volume in the opening portion,

d be the magnitude of surface tension, at the boundary between the space and the opening portion, between an opening portion inner wall and a portion of the coat that has entered the opening portion,

e be a density of the coat, and

g be a gravitational acceleration, a relationship given by

(c+a×

t)×

e×

g≦

b×

d

is satisfied.

27. A method according to claim 24, wherein

the upper electrode is formed by plating gold on and around the sacrificial film, and

the coat is formed by applying the liquid material formed from polyimide.

28. A method according to claim 27, wherein

the coat is formed by applying the liquid material formed from polyimide having photosensitivity, and

the protective film is formed in an opening portion region on the upper electrode to close the opening portions by removing a region of the coat other than a peripheral region of the opening portions by photolithography and hardening a remaining portion.

29. A method according to claim 24, wherein letting t be a thickness of the coat in a region other than the opening portions in forming the coat,

a be a sectional area of the opening portion at a boundary between the opening portion and an external portion of a space formed between the upper electrode and the lower electrode,

b be a peripheral length of a section of the opening portion at a boundary between the space and the opening portion,

c be a volume in the opening portion,

d be the magnitude of surface tension, at the boundary between the space and the opening portion, between an opening portion inner wall and a portion of the coat that has entered the opening portion,

e be a density of the coat, and

g be a gravitational acceleration, a relationship given by

(c+a×

t)×

e×

g≦

b×

d

is satisfied,

wherein the upper electrode is formed by plating gold on and around the sacrificial film, and the coat is formed by applying the liquid material formed from polyimide.