US4358745A
Expired / Lapsed
US
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Semiconductor surface acoustic wave device
Assignee: International Business Machines Corp
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Filing: 1981-03-16
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Granted: 1982-11-09
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Expires: 2001-03-16
Abstract
Abstract Surface acoustic wave devices with selectable performance parameters such as having a temperature coefficient of zero, may be fabricated employing a monocrystalline semiconductor substrate with a combination of appropriate doping and crystallographic orientation both with respect to the surface and the direction of propagation. Monocrystalline silicon doped with phosphorous to the order of 2×10 19 atoms per cc, exhibits a zero temperature coefficient at 300° Kelvin for acoustic waves propagating in the [110] crystallographic direction on a [110] substrate.
Inventors
- 👤 Robert W. Keyes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:46
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/02535; H03H9/02543
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
94 words
In a device wherein semiconductor signal processing and surface wave propagation are employed in single substrate the improvement for surface wave propagation to eliminate the use of multi-material substrates comprising a monolithic semiconductor material substrate having a surface orientation and a direction of propagation in which said surface wave velocity is affected by doping with at least one of donors and acceptors, and a doping level in at least a region of said substrate operable to reduce the effect of temperature on the propagation time of a surface acoustic wave in said semiconductor material.
Claim 2
Dependent Claim
94 words
In a device wherein semiconductor signal processing and surface wave propagation are employed in single substrate the improvement for surface wave propagation to eliminate the use of multi-material substrates comprising a monolithic semiconductor material substrate having a surface orientation and a direction of propagation in which said surface wave velocity is affected by doping with at least one of donors and acceptors, and a doping level in at least a region of said substrate operable to reduce the effect of temperature on the propagation time of a surface acoustic wave in said semiconductor material.
Claim 3
Dependent Claim
66 words
A surface acoustic wave semiconductor device having a reduced variation with temperature of propagation time of surface acoustic waves comprising: a monolithic semiconductor material substrate having both a surface orientation and a direction of propagation in which the velocity is affected by impurity doping, and having a doping level that reduces the effect of temperature on the propagation time of surface acoustic waves in said semiconductor.
Claim 4
Dependent Claim
66 words
A surface acoustic wave semiconductor device having a reduced variation with temperature of propagation time of surface acoustic waves comprising: a monolithic semiconductor material substrate having both a surface orientation and a direction of propagation in which the velocity is affected by impurity doping, and having a doping level that reduces the effect of temperature on the propagation time of surface acoustic waves in said semiconductor.
Claim 5
Dependent Claim
13 words
The device of claim 2 wherein the substrate material is a multivalley semiconductor.
Claim 6
Dependent Claim
14 words
The device of claim 2 wherein the substrate is a degenerate band p-type semiconductor.
Claim 7
Dependent Claim
21 words
The device of claim 3 wherein said substrate is n-type silicon doped in the range of 10 18 -10 21 atoms/cc.
Claim 8
Dependent Claim
38 words
The device of claim 5 wherein said dopant is phosphorous at a level of 2×10 19 and said substrate crystallographic orientation is [110] with respect to the surface and [110] with respect to the direction of wave propagation.
Claim 9
Independent Claim
77 words
A method of reducing the effect of temperature on the propagation time of surface acoustic waves in a semiconductor material comprising: selecting a surface orientation and a direction of propagation in said semiconductor material in which the velocity of surface wave propagation is affected by impurity doping; and providing impurity doping in a region of said semiconductor material at a level operable to reduce the effect of temperature on the propagation time of a surface acoustic wave.
Claim 10
Independent Claim
77 words
A method of reducing the effect of temperature on the propagation time of surface acoustic waves in a semiconductor material comprising: selecting a surface orientation and a direction of propagation in said semiconductor material in which the velocity of surface wave propagation is affected by impurity doping; and providing impurity doping in a region of said semiconductor material at a level operable to reduce the effect of temperature on the propagation time of a surface acoustic wave.
Claim 11
Dependent Claim
44 words
The method of claim 7 wherein said semiconductor material n-type is silicon, said surface orientation is the [110] direction, said direction of propagation is the [110] direction and said impurity doping is of the range of 10 18 to 10 21 atoms per cc.
Claim 12
Dependent Claim
93 words
A semiconductor device comprising a monolithic substrate having at least in a first region semiconductor signal processing capability and having at least in a second region surface acoustic wave propagation capability said acoustic wave propagation capability comprising a crystalline orientation both with respect to the direction of propagation of surface waves and a surface of said second region in which the direction of propagation of said waves is affected by doping and a doping level in said region operable to reduce the effect of temperature on the propagation time of said acoustic waves.
Claim 13
Dependent Claim
93 words
A semiconductor device comprising a monolithic substrate having at least in a first region semiconductor signal processing capability and having at least in a second region surface acoustic wave propagation capability said acoustic wave propagation capability comprising a crystalline orientation both with respect to the direction of propagation of surface waves and a surface of said second region in which the direction of propagation of said waves is affected by doping and a doping level in said region operable to reduce the effect of temperature on the propagation time of said acoustic waves.
Claim 14
Dependent Claim
57 words
The device of claim 8 wherein said substrate is n-type silicon having a doping level at least in said second region in the range of 10 18 to 10 21 atoms/cc and having at least in said second region a crystallographic orientation perpendicular to the surface of [110] and in the direction of wave propagation of [110].
References Cited (Backward Citations)
US4110653A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-11-08 | 1986-05-10 | 1986-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-08 | 1990-05-10 | 1990-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-08 | 1994-05-10 | 1994-11-09 | $7700.00 | Window Closed / Lapsed |