Interdigital capacitor and method for adjusting the same

• US 20030183884A1
• Filed: 03/26/2003
• Published: 10/02/2003
• Est. Priority Date: 03/28/2002
• Status: Active Grant

• Current Assignee: Fujitsu Quantum Devices Limited (Fujitsu Limited)
• Original Assignee: Fujitsu Quantum Devices Limited (Fujitsu Limited)
• Inventors: Miyazawa, Naoyuki
• Granted Patent: US 6,903,402 B2
• Time in Patent Office: Days
• US Class Current: 257/401
• CPC Class Codes: H01L 23/5223 Capacitor integral with wiring layers
• CPC Class Codes: H01L 27/0805 Capacitors only
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

An interdigital capacitor includes a semiconductor substrate, and a pair of comb-like electrodes formed on the semiconductor substrate. At least one of the pair of comb-like electrodes includes a cutting target portion.

Claims

1. An interdigital capacitor comprising:

a semiconductor substrate; and

a pair of comb-like electrodes formed on the semiconductor substrate,

at least one of the pair of comb-like electrodes including a cutting target portion.

2. The interdigital capacitor according to claim 1, wherein:

the pair of comb-like electrodes comprises electrode fingers and bus lines connecting the electrode fingers; and

the cutting target portion is provided in at least one of the bus lines.

3. The interdigital capacitor according to claim 1, wherein:

the pair of comb-like electrodes comprises electrode fingers and bus lines connecting the electrode fingers;

the cutting target portion is provided in at least one of the bus lines; and

the cutting target portion is narrower than other portions of the bus lines.

4. The interdigital capacitor according to claim 1, wherein:

the pair of comb-like electrodes comprises electrode fingers and bus lines connecting the electrode fingers;

the cutting target portion is provided in at least one of the bus lines; and

the cutting target portion is thinner than other portions of the bus lines.

5. The interdigital capacitor according to claim 1, wherein:

the pair of comb-like electrodes comprises electrode fingers and bus lines connecting the electrode fingers;

the cutting target portion is provided in at least one of the bus lines; and

the cutting target portion is positioned on a first side of said at least one of the bus lines opposite to a second side thereof on which the electrode fingers are provided.

6. The interdigital capacitor according to claim 1, wherein:

the pair of comb-like electrodes comprises electrode fingers and bus lines connecting the electrode fingers;

the cutting target portion is provided in at least one of the bus lines; and

the cutting target portion is away from the semiconductor substrate.

7. The interdigital capacitor according to claim 6, wherein the cutting target portion is thinner than the bus lines.

8. The interdigital capacitor according to claim 6, further comprising an insulating film between the cutting target portion and said at least one of the bus lines, the cutting target portion being electrically connected to said at least one of the bus lines by means of a via formed in the insulating film.

9. The interdigital capacitor according to claim 1, wherein at least one of the pair of comb-like electrodes has been cut off in the cutting target portion and is divided into two parts.

10. The interdigital capacitor according to claim 1, wherein the cutting target portion includes joint portions, each of which joins some of the electrode fingers and connect joined electrode fingers to a signal line.

11. The interdigital capacitor according to claim 1, wherein:

at least one of the pair of comb-like electrodes has been cut off in the cutting target portion and is divided into two parts; and

a space defined by the two parts is covered by an insulating protection film.

12. The interdigital capacitor according to claim 1, wherein the comb-like electrodes that are paired have respective cutting target portions.

18. The interdigital capacitor according to claim 1, wherein an electric circuit is formed on the semiconductor substrate, and the interdigital capacitor is a component of the electric circuit.

13. An interdigital capacitor comprising:

a semiconductor substrate; and

a pair of comb-like electrodes formed on the semiconductor substrate,

each of the pair of comb-like electrodes having first and second electrode portions,

the first and second electrode portions including electrode fingers that have at least one of different widths, lengths and gaps.

14. The interdigital capacitor according to claim 13, wherein the width and gap of the electrode fingers of the first electrode portion are greater than those of the electrode fingers of the second electrode portion.

15. The interdigital capacitor according to claim 13, wherein the length of the electrode fingers of the first electrode portion is shorter than that of the electrode fingers of the second electrode portion.

16. The interdigital capacitor according to claim 13, one of the first and second electrode portions is connected to a signal line.

17. The interdigital capacitor according to claim 13, wherein the pair of comb-like electrodes is divided into parts by cutting.

19. An interdigital capacitor comprising:

a first pair of comb-like electrodes connected to signal lines; and

a second pair of comb-like electrodes that are cut off from the first pair of comb-like electrodes and have no electrical connections to the signal lines.

20. The interdigital capacitor as claimed in claim 19, wherein the first and second pairs of comb-like electrodes are arranged side by side.

21. A semiconductor device comprising:

an interdigital capacitor formed on a semiconductor substrate; and

a circuit element formed on the semiconductor substrate,

the interdigital capacitor comprising a pair of comb-like electrodes formed on the semiconductor substrate,

at least one of the pair of comb-like electrodes including a cutting target portion.

22. A semiconductor device comprising:

an interdigital capacitor formed on a semiconductor substrate; and

a circuit element formed on the semiconductor substrate,

the interdigital capacitor comprising a pair of comb-like electrodes formed on the semiconductor substrate,

each of the pair of comb-like electrodes having first and second electrode portions,

the first and second electrode portions including electrode fingers that have at least one of different widths, lengths and gaps.

23. A semiconductor device comprising:

an interdigital capacitor formed on a semiconductor substrate; and

a circuit element formed on the semiconductor substrate,

the interdigital capacitor comprising a first pair of comb-like electrodes connected to signal lines; and

a second pair of comb-like electrodes that are cut off from the first pair of comb-like electrodes and have no electrical connections to the signal lines.

24. A communication device comprising:

a first circuit having an interdigital capacitor; and

a second circuit processing a transmit or receive signal by using an output signal of the first circuit,

the interdigital capacitor comprising;

a semiconductor substrate; and

a pair of comb-like electrodes formed on the semiconductor substrate,

at least one of the pair of comb-like electrodes including a cutting target portion.

25. A method for adjusting an interdigital capacitor comprising a pair of comb-like electrodes formed on a semiconductor substrate, and an insulating film that covers the pair of comb-like electrodes and a surface of the semiconductor substrate, the method comprising the steps of:

(a) projecting a laser beam onto the insulating film so as to form windows in the insulating film; and

(b) cutting bus lines of the pair of comb-like electrodes exposed via the windows so that each of the pair of comb-like electrodes is divided into two parts.

26. The method according to claim 25, further comprising a step of covering a protection film that covers the windows.

27. The method according to claim 25, wherein the steps (a) and (b) are repeatedly performed until the interdigital capacitance has a desired capacitance.

28. The method according to claim 25, wherein the steps (a) and (b) are initiated in an initial cutting position and are repeatedly carried out while a cutting position is changed to progressively shift closer to signal lines connected to the pair of comb-like electrodes than the initial cutting portion each time the steps (a) and (b) are carried out.

29. A method for adjusting an interdigital capacitor comprising a pair of comb-like electrodes formed on a semiconductor substrate, and an insulating film that covers the pair of comb-like electrodes and a surface of the semiconductor substrate, the method comprising the steps of:

(a) projecting a first laser beam having a first wavelength onto the insulating film so as to form windows in the insulating film; and

(b) projecting a second laser beam having a second wavelength onto portions of the comb-like electrodes exposed via the windows so as to divide each of the pair of comb-like electrodes into two parts,

the first wavelength being different from the second wavelength.

30. The method according to claim 29, further comprising a step of covering a protection film that covers the windows.

31. The method according to claim 29, wherein the steps (a) and (b) are repeatedly performed until the interdigital capacitance has a desired capacitance.

32. The method according to claim 29, wherein the steps (a) and (b) are initiated in an initial cutting position and are repeatedly carried out while a cutting position is changed to progressively shift closer to signal lines connected to the pair of comb-like electrodes than the initial cutting portion each time the steps (a) and (b) are carried out.