US3697829A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor devices with improved voltage breakdown characteristics
Assignee: General Electric Co
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Filing: 1968-12-30
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Granted: 1972-10-10
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Expires: 1988-12-30
Abstract
Abstract To improve the reverse voltage breakdown characteristics of a semiconductor body having a junction therein formed by zones of dissimilar resistivities the periphery of the body adjacent the junction is beveled. With a positive bevel (lowest cross section zone having the highest resistivity) the reverse voltage breakdown characteristics improve progressively as the angle between the junction and the beveled periphery decreases. With a negative bevel (highest cross section zone having the highest resistivity) the reverse voltage breakdown characteristics are typically optimal in the range of from 4* to 9*. With a dielectric coating on the beveled periphery the angle range may be extended to from 1* to 25*. With two-junction bodies, for example semiconductor rectifiers and controlled rectifiers, having a higher resistivity N or P central zone between P or N zones, respectively, of lower resistivity, a combination of positive and negative bevels may be employed with like or dissimilar bevel angles at each junction.
Inventors
- 👤 Gerald C Huth
- 👤 Robert L Davies
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:03
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; H10D62/102; H10D62/103; H10D62/104; H10D99/00; Y; Y10; Y10S; Y10S148/00; Y10S148/01; Y10S148/054
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
187 words
A semiconductor device including a wafer-shaped monocrystalline semiconductor body having two major faces for receiving electrical contacts and having a thickness dimension between said two major faces which is much less than the lateral extent of either major face, said body having at least two zones of different conductivity types and different impurity concentrations defining a junction therebetween having a substantially planar portion parallel to said major faces, a dielectric material having a dielectic relative permittivity greater than vacuum in intimate contact with the surface of said body and covering at least the periphery of said junction, and means for increasing the reverse breakdown voltage of said junction comprising a peripheral contour on said body, said contour being shaped in such a manner that the cross-sectional area of said body diminishes in a direction parallel to said junction planar portion to a smaller cross-sEctional area in the one of said two zones having the higher impurity concentration than in the one of said two zones having the lower impurity concentration, said contour forming an acute angle with said junction planar portion of between 4* and 25* .
Claim 2
Dependent Claim
187 words
A semiconductor device including a wafer-shaped monocrystalline semiconductor body having two major faces for receiving electrical contacts and having a thickness dimension between said two major faces which is much less than the lateral extent of either major face, said body having at least two zones of different conductivity types and different impurity concentrations defining a junction therebetween having a substantially planar portion parallel to said major faces, a dielectric material having a dielectic relative permittivity greater than vacuum in intimate contact with the surface of said body and covering at least the periphery of said junction, and means for increasing the reverse breakdown voltage of said junction comprising a peripheral contour on said body, said contour being shaped in such a manner that the cross-sectional area of said body diminishes in a direction parallel to said junction planar portion to a smaller cross-sEctional area in the one of said two zones having the higher impurity concentration than in the one of said two zones having the lower impurity concentration, said contour forming an acute angle with said junction planar portion of between 4* and 25* .
Claim 3
Dependent Claim
136 words
In a semiconductor switch device the combination of a pair of electrical contacts, a pellet of semiconductor material having two major faces, said pellet having its major faces ohmically connected between said electrical contact members whereby voltage may be applied across said major faces, said pellet having at least two zones of one conductivity type separated by and contiguous with a separating zone of opposite conductivity type and higher resistivity then either of said two zones whereby at least a pair of essentially parallel junctions are defined between said zones, the periphery of said body beveled across both junctions to provide a diminution in cross-sectional area in the direction of said junctions and so that one major face is smaller than the other, said bevel defining an acute angle with said junctions of approximately 6* .
Claim 4
Dependent Claim
136 words
In a semiconductor switch device the combination of a pair of electrical contacts, a pellet of semiconductor material having two major faces, said pellet having its major faces ohmically connected between said electrical contact members whereby voltage may be applied across said major faces, said pellet having at least two zones of one conductivity type separated by and contiguous with a separating zone of opposite conductivity type and higher resistivity then either of said two zones whereby at least a pair of essentially parallel junctions are defined between said zones, the periphery of said body beveled across both junctions to provide a diminution in cross-sectional area in the direction of said junctions and so that one major face is smaller than the other, said bevel defining an acute angle with said junctions of approximately 6* .
Claim 5
Dependent Claim
135 words
A semiconductor rectifying device including in combination a pair of electrical contacts, a pellet of semiconductor material having two major faces, said pellet having its major faces ohmically connected between said electrical contact members whereby voltage may be applied across said major faces, said pellet including a body of semiconductor material having two zones of one conductivity type separated by and contiguous with opposite sides of a zone of opposite conductivity type and a higher resistivity than either of said two zones defining two substantially planar parallel junctions between said zones, said pellet having a single bevel around its periphery whereby the cross-sectional area of said pellet diminishes in a direction parallel to said junctions, said bevel crossing both of said junctions and forming acute angles with said junctions of between four and nine degrees.
Claim 6
Dependent Claim
135 words
A semiconductor rectifying device including in combination a pair of electrical contacts, a pellet of semiconductor material having two major faces, said pellet having its major faces ohmically connected between said electrical contact members whereby voltage may be applied across said major faces, said pellet including a body of semiconductor material having two zones of one conductivity type separated by and contiguous with opposite sides of a zone of opposite conductivity type and a higher resistivity than either of said two zones defining two substantially planar parallel junctions between said zones, said pellet having a single bevel around its periphery whereby the cross-sectional area of said pellet diminishes in a direction parallel to said junctions, said bevel crossing both of said junctions and forming acute angles with said junctions of between four and nine degrees.
Claim 7
Dependent Claim
191 words
In a controlled rectifier assembly a pair of electrical contacts, a semiconductor body having two major faces, said semiconductor body including first and second zones of one conductivity type separated by and contiguous with a third zone of opposite conductivity type defining two substantially parallel junctions between said zones and a fourth zone of said opposite conductivity type set in said first zone inwardly from the outer periphery of said body defining a third junction in said body substantially parallel with said first two junctions, said pair of contacts ohmically connected to said second and fourth zones whereby a potential can be applied between said zones and an ohmic contact connected to said first zone whereby its potential can be determined relative to the potential of said second and fourth zones, said body having a bevel around its periphery which intersects said first two junctions in a manner whereby the cross-sectional area of said body diminishes in a direction parallel to said first two junctions and from said second zone toward said first zone, said bevel forming an acute angle with said first two junctions of between four and nine degrees.
Claim 8
Dependent Claim
191 words
In a controlled rectifier assembly a pair of electrical contacts, a semiconductor body having two major faces, said semiconductor body including first and second zones of one conductivity type separated by and contiguous with a third zone of opposite conductivity type defining two substantially parallel junctions between said zones and a fourth zone of said opposite conductivity type set in said first zone inwardly from the outer periphery of said body defining a third junction in said body substantially parallel with said first two junctions, said pair of contacts ohmically connected to said second and fourth zones whereby a potential can be applied between said zones and an ohmic contact connected to said first zone whereby its potential can be determined relative to the potential of said second and fourth zones, said body having a bevel around its periphery which intersects said first two junctions in a manner whereby the cross-sectional area of said body diminishes in a direction parallel to said first two junctions and from said second zone toward said first zone, said bevel forming an acute angle with said first two junctions of between four and nine degrees.
Claim 9
Dependent Claim
188 words
In a controlled rectifier assembly a pair of electrical contacts, a semiconductor body having two major faces, said semiconductor body including first and second zones of one conductivity type separated by and contiguous with a third zone of opposite conductivity type defining two substantially parallel junctions between said zones and a fourth zone of said opposite conductivity type set in said first zone inwardly from the outer periphery of said body defining a third junction in said body substantially parallel with said first two junctions, said pair of contacts ohmically connected to said second and fourth zones whereby a potential can be applied between said zones and an ohmic contact connected to said first zone whereby its potential can be determined relative to the potential of said second and fourth zoNes, said body having a bevel around its periphery which intersects said first two junctions in a manner whereby the cross-sectional area of said body diminishes in a direction parallel to said first two junctions and from said second zone toward said first zone, said bevel forming an acute angle theta with said first two junctions defined by
Claim 10
Dependent Claim
188 words
In a controlled rectifier assembly a pair of electrical contacts, a semiconductor body having two major faces, said semiconductor body including first and second zones of one conductivity type separated by and contiguous with a third zone of opposite conductivity type defining two substantially parallel junctions between said zones and a fourth zone of said opposite conductivity type set in said first zone inwardly from the outer periphery of said body defining a third junction in said body substantially parallel with said first two junctions, said pair of contacts ohmically connected to said second and fourth zones whereby a potential can be applied between said zones and an ohmic contact connected to said first zone whereby its potential can be determined relative to the potential of said second and fourth zoNes, said body having a bevel around its periphery which intersects said first two junctions in a manner whereby the cross-sectional area of said body diminishes in a direction parallel to said first two junctions and from said second zone toward said first zone, said bevel forming an acute angle theta with said first two junctions defined by
Claim 11
Dependent Claim
166 words
A silicon controlled rectifier including a silicon wafer in which are formed four successive layers alternately of P- and N-type conductivity, an anode connected to the end P-type layer, a cathode connected to the end N-type layer, the P-N junctions between the intermediate N-type layer and the two P-type layers substantially coinciding with different cross-sections of the wafer in planes parallel to the main faces of the wafer, the net significant impurity concentration in the intermediate N-type layer being less than in each of the P-type layers, and the lateral surface of the wafer being beveled in such a manner that all round the periphery of the wafer the surface of the intermediate N-type layer contiguous with the end P-type layer makes an included angle of less than 60* with the plane of the relevant junction, and the surface of the intermediate N-type layer contiguous with the intermediate P-type layer makes an included angle of between 170* and 179* with the plane of the relevant junction.
Claim 12
Dependent Claim
166 words
A silicon controlled rectifier including a silicon wafer in which are formed four successive layers alternately of P- and N-type conductivity, an anode connected to the end P-type layer, a cathode connected to the end N-type layer, the P-N junctions between the intermediate N-type layer and the two P-type layers substantially coinciding with different cross-sections of the wafer in planes parallel to the main faces of the wafer, the net significant impurity concentration in the intermediate N-type layer being less than in each of the P-type layers, and the lateral surface of the wafer being beveled in such a manner that all round the periphery of the wafer the surface of the intermediate N-type layer contiguous with the end P-type layer makes an included angle of less than 60* with the plane of the relevant junction, and the surface of the intermediate N-type layer contiguous with the intermediate P-type layer makes an included angle of between 170* and 179* with the plane of the relevant junction.
Claim 13
Dependent Claim
19 words
A controlled rectifier as defined in claim 6 wherein a gate is connected to the intermediate P type layer.
Claim 14
Dependent Claim
112 words
A semiconductor rectifying device including a pellet of semiconductor material having two zones of one conductivity type separated by and contiguous with opposite sides of an inner zone having the opposite conductivity type and a higher resistivity than either of said two zones, said two zones and said inner zone defining two substantially planar parallel junctions therebetween, said pellet having a bevel around its periphery which bevels at least two contiguous zones whereby the cross-sectional area of said pellet diminishes in a direction parallel to said junctions, said bevel forming an acute angle theta with the plane of said junction between said two contiguous zones, said acute angle theta being defined by
Claim 15
Dependent Claim
112 words
A semiconductor rectifying device including a pellet of semiconductor material having two zones of one conductivity type separated by and contiguous with opposite sides of an inner zone having the opposite conductivity type and a higher resistivity than either of said two zones, said two zones and said inner zone defining two substantially planar parallel junctions therebetween, said pellet having a bevel around its periphery which bevels at least two contiguous zones whereby the cross-sectional area of said pellet diminishes in a direction parallel to said junctions, said bevel forming an acute angle theta with the plane of said junction between said two contiguous zones, said acute angle theta being defined by
Claim 16
Dependent Claim
124 words
A semiconductor switching device including in combination a pair of electrical contacts, a pellet of semiconductor material having two major faces, said pellet having its major faces ohmically connected between said electrical contact members whereby voltage may be applied across said major faces, said pellet of semiconductor material having two zones of one condUctivity type separated by and contiguous with opposite sides of an inner zone having opposite conductivity type and a higher resistivity than either of said two zones defining two substantially planar parallel junctions between said zones, said pellet having a bevel around its periphery whereby the cross-sectional area of said pellet diminishes in a direction parallel to said junctions, said bevel forming an acute angle theta with said junctions defined by
Claim 17
Dependent Claim
124 words
A semiconductor switching device including in combination a pair of electrical contacts, a pellet of semiconductor material having two major faces, said pellet having its major faces ohmically connected between said electrical contact members whereby voltage may be applied across said major faces, said pellet of semiconductor material having two zones of one condUctivity type separated by and contiguous with opposite sides of an inner zone having opposite conductivity type and a higher resistivity than either of said two zones defining two substantially planar parallel junctions between said zones, said pellet having a bevel around its periphery whereby the cross-sectional area of said pellet diminishes in a direction parallel to said junctions, said bevel forming an acute angle theta with said junctions defined by
Claim 18
Dependent Claim
151 words
In a semiconductor switch, a pair of electrical contacts, a pellet of semiconductor material having two major faces, said pellet having its major faces ohmically connected between said electrical contact members whereby voltage may be applied across said major faces, a hermetically sealed enclosure enclosing said pellet and contact assembly, and electrical connectors connected to said contacts and extending outside said enclosure whereby voltage may be applied to said contacts, a pellet of semiconductor material having two zones of one conductivity type separated by and contiguous with opposite sides of an inner zone having opposite conductivity type and a higher resistivity than either of said two zones defining two substantially planar parallel junctions between said zones, said pellet having a bevel around its periphery whereby the cross-sectional area of said pellet diminishes in a direction parallel to said junctions, said bevel forming an acute angle theta with said junctions defined by
Claim 19
Dependent Claim
151 words
In a semiconductor switch, a pair of electrical contacts, a pellet of semiconductor material having two major faces, said pellet having its major faces ohmically connected between said electrical contact members whereby voltage may be applied across said major faces, a hermetically sealed enclosure enclosing said pellet and contact assembly, and electrical connectors connected to said contacts and extending outside said enclosure whereby voltage may be applied to said contacts, a pellet of semiconductor material having two zones of one conductivity type separated by and contiguous with opposite sides of an inner zone having opposite conductivity type and a higher resistivity than either of said two zones defining two substantially planar parallel junctions between said zones, said pellet having a bevel around its periphery whereby the cross-sectional area of said pellet diminishes in a direction parallel to said junctions, said bevel forming an acute angle theta with said junctions defined by
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-10 | 1976-04-10 | 1976-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-10 | 1980-04-10 | 1980-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-10 | 1984-04-10 | 1984-10-10 | $7700.00 | Window Closed / Lapsed |