High frequency switch circuit device

• US 6,870,241 B2
• Filed: 11/27/2001
• Issued: 03/22/2005
• Est. Priority Date: 11/27/2000
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Imanishi, Ikuo, Ito, Junji, Nakatani, Toshifumi
• Primary Examiner(s): Thomas, Tom
• Assistant Examiner(s): Warren, Matthew E.
• Application Number:
  US09/993,712
• Publication Number:
  US 20020063270A1
• Time in Patent Office: 1,211 Days
• Field of Search: 257/347, 257/379, 257/516, 257/528, 257/531, 257/536, 327/308, 327/403, 333/101, 333/103
• US Class Current: 257/531
• CPC Class Codes: H01L 27/0617 comprising components of the field-effect type H01L27/0251 takes precedence

Abstract

A high frequency switch circuit device includes an FET to be a switching element on a semiconductor substrate. The FET includes an n-type well, a gate electrode, a source layer and a drain layer. An n-type well line to be connected to an n-type well layer to be a back gate is connected to a voltage supply node via an inductor. The flow of a high frequency signal between the voltage supply node and the n-type well layer is blocked by the inductor, and the flow of a high frequency signal in the vertical direction is blocked by a depletion layer extending between the n-type well and a p-type substrate region. Moreover, the flow of a high frequency signal in the horizontal direction is blocked by a trench separation insulative layer.

Claims

1. A high frequency switch circuit device, comprising:

a semiconductor substrate including a p-type substrate region;

a p-channel type FET provided in the p-type substrate region and functioning as a high frequency switching element including a source, a drain, a gate and an n-type well;

a voltage supply node connected to the n-type well for supplying a voltage to the n-type well;

high frequency signal separation means provided between the n-type well and the voltage supply node for separating a high frequency component of a signal flowing between the n-type well and the voltage supply node;

a source electrode connected to the source, wherein said source electrode is separated from an electrode of the n-type well; and

an input signal node connected to the source.

2. The high frequency switch circuit device of claim 1, further comprising an insulative separation layer surrounding the n-type well and extending downward from a surface of the semiconductor substrate to a position deeper than the n-type well.

3. The high frequency switch circuit device of claim 1, wherein the semiconductor substrate is an SOI substrate obtained by providing the n-type well on an insulator layer.

4. The high frequency switch circuit device of claim 3, wherein the SOI substrate is a silicon substrate having a buried insulative layer made of silicon oxide.

5. The high frequency switch circuit device of claim 3, wherein the SOI substrate is obtained by epitaxially growing a silicon crystal layer on a sapphire substrate.

6. The high frequency switch circuit device of claim 1, further comprising another high frequency signal separation means provided between the n-type well and a ground so as to separate a high frequency component of a signal flowing between the n-type well and the ground.

7. The high frequency switch circuit device of claim 1, wherein the high frequency signal separation means is an inductor.

8. The high frequency switch circuit device of claim 7, wherein the inductor is a coil-shaped line formed on the semiconductor substrate.

9. The high frequency switch circuit device of claim 1, wherein the high frequency signal separation means is a resistor.

10. The high frequency switch circuit device of claim 9, wherein the resistor is a polysilicon film formed on the semiconductor substrate.

11. The high frequency switch circuit device of claim 1, wherein the high frequency signal separation means is a line having a line length that is an odd number multiple of ¼

of a wavelength of a signal passing therethrough.

12. The high frequency switch circuit device of claim 11, wherein the line is formed on the semiconductor substrate.

13. The high frequency switch circuit device of claim 1, further comprising a drain electrode connected to the drain, wherein said drain electrode is separated from an electrode of the n-type well.

14. A high frequency switch circuit device, comprising:

a semiconductor substrate including a p-type substrate region;

an n-channel type FET provided in the p-type substrate region and functioning as a high frequency switching element including a source, a drain, a gate and a p-type well;

a barrier layer provided between the p-type substrate region and the p-type well and serving as a barrier against a flow of a high frequency signal between the p-type substrate region and the p-type well;

high frequency signal separation means provided between the p-type well and a ground for separating a high frequency component of a signal flowing between the p-type well and the ground;

a source electrode connected to the source, wherein said source electrode is separated from an electrode of the p-type well; and

an input signal node connected to the source.

15. The high frequency switch circuit device of claim 14, wherein:

the barrier layer is an n-type well provided between the p-type substrate region and the p-type well, the high frequency switch circuit device further comprising;

a voltage supply node connected to the n-type well for supplying a voltage to the n-type well; and

another high frequency signal separation means provided between the n-type well and the voltage supply node so as to separate a high frequency component of a signal flowing between the n-type well and the voltage supply node.

16. The high frequency switch circuit device of claim 14, further comprising an insulative separation layer surrounding the p-type well and extending downward from a surface of the semiconductor substrate to a position deeper than the p-type well.

17. The high frequency switch circuit device of claim 14, wherein the semiconductor substrate is an SOI substrate obtained by providing the p-type well on an insulator layer.

18. The high frequency switch circuit device of claim 17, wherein the SOI substrate is a silicon substrate having a buried insulative layer made of silicon oxide.

19. The high frequency switch circuit device of claim 17, wherein the SOI substrate is obtained by epitaxially growing a silicon crystal layer on a sapphire substrate.

20. The high frequency switch circuit device of claim 14, further comprising another high frequency signal separation means provided between the p-type well and a ground so as to separate a high frequency component of a signal flowing between the p-type well and the ground.

21. The high frequency switch circuit device of claim 14, wherein the high frequency signal separation means is an inductor.

22. The high frequency switch circuit device of claim 21, wherein the inductor is a coil-shaped line formed on the semiconductor substrate.

23. The high frequency switch circuit device of claim 14, wherein the high frequency signal separation means is a resistor.

24. The high frequency switch circuit device of claim 23, wherein the resistor is a polysilicon film formed on the semiconductor substrate.

25. The high frequency switch circuit device of claim 14, wherein the high frequency signal separation means is a line having a line length that is an odd number multiple of ¼

of a wavelength of a signal passing therethrough.

26. The high frequency switch circuit device of claim 25, wherein the line is formed on the semiconductor substrate.

27. The high frequency switch circuit device of claim 14, further comprising a drain electrode connected to the drain, wherein said drain electrode is separated from an electrode of the p-type well.