Semiconductor device with a resonator using acoustic standing wave excited in semiconductor crystal

• US 9,117,931 B2
• Filed: 11/27/2012
• Issued: 08/25/2015
• Est. Priority Date: 03/29/2012
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Abe, Kazuhide, Iida, Atsuko, Itaya, Kazuhiko, Wadatsumi, Junji, Kousai, Shouhei
• Primary Examiner(s): Le, Thao X
• Assistant Examiner(s): IDA, GEOFFREY H
• Application Number:
  US13/685,859
• Publication Number:
  US 20130256660A1
• Time in Patent Office: 1,001 Days
• Field of Search: 257/48, 331/176
• US Class Current: 1/1
• CPC Class Codes: H01L 29/84 controllable by variation of applied mechanical force, e.g. of pressure
• CPC Class Codes: H01L 2924/1461 MEMS
• CPC Class Codes: H03H 2009/02314 forming part of a transistor structure
• CPC Class Codes: H03H 9/2405 of microelectro-mechanical resonators

Abstract

A semiconductor device according to an embodiment has: a semiconductor substrate; an acoustic resonator formed on the semiconductor substrate, having a semiconductor layer including impurity electrically isolated from the substrate by depletion layer and configured to resonate at a predetermined resonance frequency based on acoustic standing wave excited in the semiconductor layer; a temperature detector formed on the semiconductor substrate and configured to detect temperature of the semiconductor substrate; a calculating unit formed on the semiconductor substrate and configured to perform calculation of temperature compensation based on the temperature detected by the temperature detector, kind of the impurity and concentration of the impurity; and a controller formed on the semiconductor substrate and configured to control the resonance frequency based on a result of the calculation by the calculating unit.

Claims

1. A semiconductor device comprising:

a first conductive type semiconductor substrate;

an acoustic resonator formed on the semiconductor substrate, the acoustic resonator comprising a first conductive type semiconductor layer including first conductive type impurity, the semiconductor layer is electrically isolated from the semiconductor substrate by a second conductive type semiconductor well region both in direction vertical to a surface of the semiconductor layer and in direction parallel to the surface of the semiconductor layer, the semiconductor layer being surrounded by the semiconductor well region at the surface of the semiconductor layer, a device isolation structure surrounding the semiconductor layer forms a boundary between the semiconductor layer and the semiconductor well region at the surface of the semiconductor layer, the acoustic resonator resonates at a resonance frequency based on acoustic standing wave excited in the semiconductor layer, the semiconductor substrate, the semiconductor layer and the semiconductor well region are formed in a same single crystal;

at least one electric terminal provided directly on the surface of the semiconductor layer;

a temperature detector formed on the semiconductor substrate, the temperature detector detects temperature of the semiconductor substrate;

a calculating unit formed on the semiconductor substrate, the calculating unit performs calculation of temperature compensation based on the temperature detected by the temperature detector, kind of the impurity and concentration of the impurity; and

a controller formed on the semiconductor substrate, the controller controls the resonance frequency based on a result of the calculation by the calculating unit.

2. The device according to claim 1,

wherein the acoustic standing wave is excited by application of a pulse voltage to the semiconductor layer incorporated with deformation potential effect.

3. The device according to claim 1,

wherein the same single crystal is silicon.

4. The device according to claim 1,

wherein the acoustic standing wave is excited by electric carrier collisions incorporated with phonon emission.

5. A semiconductor device comprising:

a first conductive type semiconductor substrate;

a first acoustic resonator formed on the semiconductor substrate, the first acoustic resonator comprising a first conductive type first semiconductor layer including first conductive type first impurity concentration, the first semiconductor layer is electrically isolated from the semiconductor substrate by a second conductive type first semiconductor well region both in direction vertical to a surface of the first semiconductor layer and in direction parallel to the surface of the first semiconductor layer, the first semiconductor layer being surrounded by the first semiconductor well region at the surface of the first semiconductor layer, a first device isolation structure surrounding the first semiconductor layer forms a first boundary between the first semiconductor layer and the first semiconductor well region at the surface of the first semiconductor layer, the first acoustic resonator resonates at a first resonance frequency based on acoustic standing wave excited in the first semiconductor layer, the semiconductor substrate, the first semiconductor layer and the first semiconductor well region are formed in a same single crystal;

at least one electric terminal provided directly on the surface of the first semiconductor layer;

a first oscillator formed on the semiconductor substrate, the first oscillator oscillates at a first oscillation frequency depending on the first resonance frequency;

a second acoustic resonator formed on the semiconductor substrate, the second acoustic resonator comprising a first conductive type second semiconductor layer including first conductive type second impurity, the second impurity has concentration different from the first impurity concentration, the second semiconductor layer is electrically isolated from the semiconductor substrate by a second conductive type second semiconductor well region both in direction vertical to a surface of the second semiconductor layer and in direction parallel to the surface of the second semiconductor layer, the second semiconductor layer being surrounded by the second semiconductor well region at the surface of the second semiconductor layer, a second device isolation structure surrounding the second semiconductor layer forms a second boundary between the second semiconductor layer and the second semiconductor well region at the surface of the second semiconductor layer, the second acoustic resonator resonates at a second resonance frequency based on acoustic standing wave excited in the second semiconductor layer, the semiconductor substrate, the second semiconductor layer and the second semiconductor well region are formed in the same single crystal;

at least one electric terminal provided directly on the surface of the second semiconductor layer;

a second oscillator formed on the semiconductor substrate, the second oscillator oscillates at a second oscillation frequency depending on the second resonance frequency;

a temperature detector formed on the semiconductor substrate, the temperature detector detects temperature of the semiconductor substrate;

a calculating unit formed on the semiconductor substrate, the calculating unit performs calculation of temperature compensation based on the temperature detected by the temperature detector, kind of the impurity, the first impurity concentration, the second impurity concentration, the first oscillation frequency and the second oscillation frequency; and

a controller formed on the semiconductor substrate, the controller controls the first oscillation frequency and the second oscillation frequency based on a result of the calculation by the calculating unit.

6. The device according to claim 5,

wherein the calculating unit comprises a difference calculating unit calculates difference between the first oscillation frequency and the second oscillation frequency.

7. The device according to claim 5,

wherein the controller generates a first direct-current voltage applied to the first semiconductor layer and a second direct-current voltage applied to the second semiconductor layer.

8. The device according to claim 5,

wherein the acoustic standing wave is excited by application of respective pulse voltages to the first semiconductor layer and the second semiconductor layer, the first and second semiconductor layers include indirect band gap type semiconductor.

9. The device according to claim 5,

wherein the same single crystal is silicon.

10. The device according to claim 5,

the acoustic standing wave is excited by electric carrier collision incorporated with phonon emission.

11. The device according to claim 5,

wherein the first impurity concentration and the second impurity concentration both are not lower than 10¹⁷ atoms/cm³ and not higher than 10²⁰ atoms/cm³.

12. The device according to claim 5,

wherein difference between the first impurity concentration and the second impurity concentration is equal to or more than 1%.

13. A semiconductor device comprising:

a first conductive type semiconductor substrate;

an acoustic resonator formed on the semiconductor substrate, the acoustic resonator comprising a first conductive type semiconductor layer including first conductive type impurity, the semiconductor layer is electrically isolated from the semiconductor substrate by a second conductive type semiconductor well region both in direction vertical to a surface of the semiconductor layer and in direction parallel to the surface of the semiconductor layer, the semiconductor layer being surrounded by the semiconductor well region at the surface of the semiconductor layer, a device isolation structure surrounding the semiconductor layer forms a boundary between the semiconductor layer and the semiconductor well region at the surface of the semiconductor layer, the acoustic resonator resonates at a predetermined resonance frequency based on acoustic standing wave excited in the semiconductor layer, the semiconductor substrate, the semiconductor layer and the semiconductor well region are formed in a same single crystal;

at least one electric terminal provided directly on the surface of the semiconductor layer;

an oscillator formed on the semiconductor substrate, the oscillator oscillates at an oscillation frequency depending on the resonance frequency;

a temperature detector formed on the semiconductor substrate, the temperature detector detects temperature of the semiconductor substrate;

a calculating unit formed on the semiconductor substrate, the calculating unit performs calculation of temperature compensation based on the temperature detected by the temperature detector, kind of the impurity, concentration of the impurity and the oscillation frequency of the oscillator;

a memory unit formed on the semiconductor substrate, the memory unit stores information used in the calculation; and

a controller formed on the semiconductor substrate, the controller controls the resonance frequency based on a result of the calculation by the calculating unit.

14. The device according to claim 13,

wherein the information includes a coefficient of an expression used in the calculation.

15. The device according to claim 13,

wherein the controller generates a direct-current voltage applied to the semiconductor layer.

16. The device according to claim 13,

wherein the same single crystal is silicon.

17. The device according to claim 13,

wherein the acoustic standing wave is excited by electric carrier collisions incorporated with phonon emission.