Patent USH569H successfully refreshed from Google Patents.
USH569H
Expired / Lapsed
US
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Charge storage depletion region discharge protection
Assignee: Motorola Solutions Inc
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Filing: 1986-12-04
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Granted: 1989-01-03
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Expires: 2006-12-04
Abstract
Abstract A means and method is described for shielding semiconductor charge storage devices from the effects of particles or ionizing radiation absorbed within the bulk of the semiconductor substrate, by providing a free carrier shield consisting of a buried layer of very low lifetime in the undisturbed material below the depletion regions associated with the charge storage devices. The very low lifetime layer is obtained by ion implantation of a super-saturated zone of impurities such as oxygen which provide deep recombination centers and which react chemically with the substrate material so as to provide thermally stable complexes which do not anneal away during post implant heating cycles. Concentrations of lifetime killing impurities significantly exceeding the solid solubility limit are achieved so that the lifetime reduction in the carrier shield region greatly exceeds that obtainable by prior art methods. Partial shielding is also provided against carriers injected by nearby junctions or introduced by charge pumping during circuit operation.
Inventors
- 👤 Charles J. Varker
- 👤 Syd R. Wilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:18
CPC Classifications
H; H10; H10P; H10P30/00; H10P30/20; H10P30/202; H10P30/204; H10B; H10B12/00; H10B12/30; H10D; H10D62/00; H10D62/10; H10D62/17; H10D62/80; H10D62/83; H10D62/834; H10P30/208
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
134 words
A semiconductor device comprising: a single crystal silicon substrate having first and second major surfaces separated by a first distance; a first semiconducting region located in said substrate adjacent said first surface and having a first thickness and a first lifetime for charge storage devices; and a second region in said substrate underlying said first region and having a second lifetime lower than said first lifetime, wherein said second region has been implanted with oxygen to provide in said second region an oxygen concentration higher than adjacent regions and having a peak value exceeding a solid solubility limit of oxygen in silicon but less than a value for forming an insulating layer of silicon oxide, and wherein said second oxygen containing region has a second thickness that is small compared to said first distance.
Claim 2
Dependent Claim
134 words
A semiconductor device comprising: a single crystal silicon substrate having first and second major surfaces separated by a first distance; a first semiconducting region located in said substrate adjacent said first surface and having a first thickness and a first lifetime for charge storage devices; and a second region in said substrate underlying said first region and having a second lifetime lower than said first lifetime, wherein said second region has been implanted with oxygen to provide in said second region an oxygen concentration higher than adjacent regions and having a peak value exceeding a solid solubility limit of oxygen in silicon but less than a value for forming an insulating layer of silicon oxide, and wherein said second oxygen containing region has a second thickness that is small compared to said first distance.
Claim 3
Dependent Claim
15 words
The device of claim 1 wherein said second thickness is about four microns or less.
Claim 4
Dependent Claim
120 words
A semiconductor device comprising: a single crystal silicon substrate having first and second surfaces separated by a first distance and first and second superposed semiconductor regions underlying said first surface and separated from said second surface by a second distance; wherein said first region, adjacent said first surface, has a first lifetime for constructing charge storage devices; wherein said second region, underlying said first region and separated from said second surface by said second distance, has a peak concentration of oxygen exceeding a solid solubility of oxygen in silicon at the melting point of silicon but less than a concentration for an insulating silicon oxide layer; and wherein said second region has a thickness small compared to said second distance.
Claim 5
Dependent Claim
120 words
A semiconductor device comprising: a single crystal silicon substrate having first and second surfaces separated by a first distance and first and second superposed semiconductor regions underlying said first surface and separated from said second surface by a second distance; wherein said first region, adjacent said first surface, has a first lifetime for constructing charge storage devices; wherein said second region, underlying said first region and separated from said second surface by said second distance, has a peak concentration of oxygen exceeding a solid solubility of oxygen in silicon at the melting point of silicon but less than a concentration for an insulating silicon oxide layer; and wherein said second region has a thickness small compared to said second distance.
Claim 6
Dependent Claim
29 words
The device of claim 3 wherein said substrate has a first lateral extent and wherein said second region has a second lateral extent less than said first lateral extent.
Claim 7
Dependent Claim
151 words
A semiconductor device comprising: a single crystal semiconductor substrate having first and second major surfaces separated by a first distance; wherein said substrate contains a first region adjacent said first surface and of a first thickness small compared to said first distance and having a lifetime for charge storage devices; wherein said substrate contains a second oxygen and carbon containing region of low lifetime relative to said first region underlying said first region and of a second thickness; wherein said oxygen concentration in said second region exceeds a solid solubility limit for oxygen in said substrate but less than an amount for forming an insulating oxide layer in said second region; wherein said substrate contains a third region of a third thickness between said second region and said second surface, and having lower oxygen concentrations than said second region; and wherein said second thickness is small compared to said third thickness.
Claim 8
Dependent Claim
151 words
A semiconductor device comprising: a single crystal semiconductor substrate having first and second major surfaces separated by a first distance; wherein said substrate contains a first region adjacent said first surface and of a first thickness small compared to said first distance and having a lifetime for charge storage devices; wherein said substrate contains a second oxygen and carbon containing region of low lifetime relative to said first region underlying said first region and of a second thickness; wherein said oxygen concentration in said second region exceeds a solid solubility limit for oxygen in said substrate but less than an amount for forming an insulating oxide layer in said second region; wherein said substrate contains a third region of a third thickness between said second region and said second surface, and having lower oxygen concentrations than said second region; and wherein said second thickness is small compared to said third thickness.
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