US4683395A
Expired / Lapsed
US
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Surface acoustic wave device
Assignee: Faurecia Clarion Electronics Co Ltd
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Filing: 1986-09-08
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Granted: 1987-07-28
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Expires: 2006-09-08
Abstract
Abstract A monolithic surface acoustic wave convolver has a structure of piezoelectric layer/insulative layer/p(n)-type semiconductive layer/n(p)-type semiconductive layer/n + (p + )-type semiconductive substrate in which the p(n)-type semiconductive layer has a uniform thickness, and its acceptor (donor) concentration and thickness are selected to allow a depletion layer to expand throughout it under zero bias. The p(n)-type semiconductive layer and n(p)-type semiconductive layer are made by epitaxially growing the n(p)-type semiconductive layer on the n + (p + )-type semiconductive substrate and subsequently change the conductivity of the surface portion of the epitaxial layer by impurity diffusion or ion implantation.
Inventors
- 👤 Syuichi Mitsutsuka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:07
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/12; G06G7/19; G06G7/195
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
119 words
A surface acoustic wave device comprising: a low-resistance semiconductive substrate in a first conductivity; a semiconductive layer in the first conductivity provided on said substrate; a semiconductive layer in a second conductivity provided on said first conductivity semiconductive substrate; an insulative layer provided on said second conductivity semiconductive layer; a piezoelectric layer provided on said insulative layer; a gate electrode provided on said piezoelectric layer; two comb-shaped electrodes provided on opposite sides of said gate electrode; and a bias voltage source connected to said gate electrode, said second conductivity semiconductive layer having an impurity concentration and a thickness which allow a depletion layer to expand throughout it when a bias voltage supplied from said bias voltage source is zero.
Claim 2
Dependent Claim
119 words
A surface acoustic wave device comprising: a low-resistance semiconductive substrate in a first conductivity; a semiconductive layer in the first conductivity provided on said substrate; a semiconductive layer in a second conductivity provided on said first conductivity semiconductive substrate; an insulative layer provided on said second conductivity semiconductive layer; a piezoelectric layer provided on said insulative layer; a gate electrode provided on said piezoelectric layer; two comb-shaped electrodes provided on opposite sides of said gate electrode; and a bias voltage source connected to said gate electrode, said second conductivity semiconductive layer having an impurity concentration and a thickness which allow a depletion layer to expand throughout it when a bias voltage supplied from said bias voltage source is zero.
Claim 3
Dependent Claim
47 words
A surface acoustic wave device of claim 1 wherein said substrate is an n + -type semiconductor, said first conductivity semiconductive layer is an n-type semiconductive epitaxial layer, and said second conductivity semiconductive layer is the surface of said epitaxial layer changed to a p-type semiconductive layer.
Claim 4
Dependent Claim
47 words
A surface acoustic wave device of claim 2 wherein said substrate is a p + -type semiconductor, said first conductivity semiconductive layer is a p-type semiconductive epitaxial layer, and said second conductivity semiconductive layer is the surface of said epitaxial layer changed to an n-type semiconductive layer.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-07-27 | 1991-01-26 | 1991-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-27 | 1995-01-26 | 1995-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-27 | 1999-01-26 | 1999-07-28 | $7700.00 | Window Closed / Lapsed |