High frequency insulated gate field effect transistor with protective diodes

Claim 2

A high frequency insulated gate field-effect transistor comprising an integrated semiconductor crystal having a substrate of first conductivity type, a uniformly thin semiconductor layer of a second conductivity type overlying said substrate and higher in impurity concentration than said substrate, a base region of said first conductivity type integrated into said semiconductor layer to a depth sufficient to electrically connect it to said substrate, a source region of said second conductivity type integrated into said base region, a gate insulator overlying said semiconductor layer, a gate electrode overlying said gate insulator, a drain region of said second conductivity type integrated into said semiconductor layer, and a protective element for protection against the breakdown of said insulator, said protective element being integrated in the same semiconductor crystal in which said field-effect transistor is integrated comprising two reverse connected p-n junctions, said two p-n junctions comprising three semiconductor regions one of which is disposed between the other two regions is different in conductivity type from said other two regions and higher in impurity concentration than the other two regions at said junctions thereby suppressing minority carrier injection, one of said two regions being of said first conductivity type and integrated into said semiconductor layer and being electrically connected to said gate electrode, and the other of said two regions being electrically conneCted to said source, said semiconductor layer being said region of higher impurity concentration between said two regions of said protective element.

Claim 3

A high frequency insulated gate field - effect transistor comprising an integrated semiconductor crystal having a substrate of first conductivity type, a uniformly thin semiconductor layer of a second conductivity type overlying said substrate and higher in impurity concentration than said substrate, a base region of said first conductivity type integrated into said semiconductor layer to a depth sufficient to electrically connect it to said substrate, a source region of said second conductivity type integrated into said base region, a gate insulator overlying said semiconductor layer, a gate electrode overlying said gate insulator, a drain region of said second conductivity type integrated into said semiconductor layer, and a protective element for protection against the breakdown of said gate insulator, said protective element being integrated in the same semiconductor crystal in which said field-effect transistor is integrated, comprising two reverse connected p-n junctions, said two p-n junctions comprising three semiconductor regions one of which is disposed between the other two regions is different in conductivity type from the other two regions and higher in impurity concentration than said other two regions at said junctions thereby suppressing minority carrier injection, one of said two regions being electrically connected to said gate electrode and the other of said two regions being electrically connected to the same semiconductor substrate as that of said field effect transistor, said semiconductor layer being said region of higher impurity concentration between said two regions of said protective element.

Claim 4

A high frequency insulated gate field - effect transistor comprising an integrated semiconductor crystal having a substrate of first conductivity type, a uniformly thin semiconductor layer of a second conductivity type overlying said substrate and higher in impurity concentration than said substrate, a base region of said first conductivity type integrated into said semiconductor layer to a depth sufficient to electrically connect it to said substrate, a source region of said second conductivity type integrated into said base region, a gate insulator overlying said semiconductor layer, a gate electrode overlying said gate insulator, a drain region of said second conductivity type integrated into said semiconductor layer, and a protective element for protection against the breakdown of said gate insulator, said protective element being integrated in the same semiconductor crystal in which said field-effect transistor is integrated, comprising two reverse connected p-n junctions, said two p-n junctions comprising three semiconductor regions one of which is disposed between the other two regions is different in conductivity type from the other two regions and higher in impurity concentration than said other two regions at said junctions thereby suppressing minority carrier injection, one of said two regions being electrically connected to said gate electrode and the other of said two regions being electrically connected to the same semiconductor substrate as that of said field effect transistor, said semiconductor layer being said region of higher impurity concentration between said two regions of said protective element.

Claim 5

A high frequency insulated gate field-effect transistor comprising in integrated semiconductor crystal having a substrate of first conductivity type, a uniformly thin semiconductor layer of a second conductivity type overlying said substrate and higher in impurity concentration than said substrate, a base region of said first conductivity type integrated into said semiconductor layer to a depth sufficient to electrically connect it to said substrate, a source region of said second conductivity type integrated into said base region, a gate insulator overlying said semiconductor layer, a gate electrode overlying said gate insulator, a drain region of said second conductivity type integrated into said semiconductor layer, and a protective element for protection against the breakdown of said gate insulator, said protective element being integrated in the same semiconductor crystal in which said field-effect transistor is integrated comprising two reverse connected p-n junctions, said two p-n junctions comprising three semiconductor regions one of which is disposed between the other two regions is different in conductivity type from said other two regions is higher in impurity concentration than the other two regions at said junctions thereby suppressing minority carrier injection, one of said two regions being electrically connected to said gate electrode and the other of said two regions being said semiconductor substrate itself, said semiconductor layer being said region of higher impurity concentration between said two regions of said protective element.

Claim 6

A high frequency insulated gate field-effect transistor comprising in integrated semiconductor crystal having a substrate of first conductivity type, a uniformly thin semiconductor layer of a second conductivity type overlying said substrate and higher in impurity concentration than said substrate, a base region of said first conductivity type integrated into said semiconductor layer to a depth sufficient to electrically connect it to said substrate, a source region of said second conductivity type integrated into said base region, a gate insulator overlying said semiconductor layer, a gate electrode overlying said gate insulator, a drain region of said second conductivity type integrated into said semiconductor layer, and a protective element for protection against the breakdown of said gate insulator, said protective element being integrated in the same semiconductor crystal in which said field-effect transistor is integrated comprising two reverse connected p-n junctions, said two p-n junctions comprising three semiconductor regions one of which is disposed between the other two regions is different in conductivity type from said other two regions is higher in impurity concentration than the other two regions at said junctions thereby suppressing minority carrier injection, one of said two regions being electrically connected to said gate electrode and the other of said two regions being said semiconductor substrate itself, said semiconductor layer being said region of higher impurity concentration between said two regions of said protective element.

Claim 7

A high frequency insulated gate field-effect transistor comprising a substrate of first conductivity type, a uniformly thin semiconductor layer of a second conductivity type overlying said substrate and higher in impurity concentration than said substrate, a base region of said first conductivity type integrated into said semiconductor layer to a depth sufficient to electrically connect it to said substrate, a source region of said second conductivity type integrated into said base region, a gate insulator overlying said semiconductor layer, a gate electrode overlying said gate insulator, a drain region of said second conductivity type integrated into sAid semiconductor layer, and a protective element for protection against the breakdown of said gate insulator, said protective element being integrated in the same semiconductor crystal comprising said field-effect transistor and comprising a reverse connected p-n junction and a Schottky junction thereby suppressing minority carrier injection, said p-n junction comprising at least two semiconductor regions I, II different in conductivity type and impurity concentration, said Schottky junction being formed on said semiconductor region I forming a p-n junction, said region I having higher impurity concentration at said p-n junction than another said region II forming said p-n junction, said Schottky junction and said p-n junction thereby establish means effective to suppress minority carrier injection, one of the materials forming said Schottky junction and the said region II forming said p-n junction being electrically connected to said gate electrode, the remainder being electrically connected to said substrate of said field-effect transistor.

Claim 8

A high frequency insulated gate field-effect transistor comprising a substrate of first conductivity type, a uniformly thin semiconductor layer of a second conductivity type overlying said substrate and higher in impurity concentration than said substrate, a base region of said first conductivity type integrated into said semiconductor layer to a depth sufficient to electrically connect it to said substrate, a source region of said second conductivity type integrated into said base region, a gate insulator overlying said semiconductor layer, a gate electrode overlying said gate insulator, a drain region of said second conductivity type integrated into sAid semiconductor layer, and a protective element for protection against the breakdown of said gate insulator, said protective element being integrated in the same semiconductor crystal comprising said field-effect transistor and comprising a reverse connected p-n junction and a Schottky junction thereby suppressing minority carrier injection, said p-n junction comprising at least two semiconductor regions I, II different in conductivity type and impurity concentration, said Schottky junction being formed on said semiconductor region I forming a p-n junction, said region I having higher impurity concentration at said p-n junction than another said region II forming said p-n junction, said Schottky junction and said p-n junction thereby establish means effective to suppress minority carrier injection, one of the materials forming said Schottky junction and the said region II forming said p-n junction being electrically connected to said gate electrode, the remainder being electrically connected to said substrate of said field-effect transistor.

Claim 9

A high frequency insulated gate field-effect transistor comprising a substrate of a first conductivity type, a uniformly thin semiconductor layer of a second conductivity type overlying said substrate and higher in impurity concentration than said substrate, a base region of said first conductivity type integrated into said semiconductor layer to a depth sufficient to electrically connect it to said substrate, a source region of said second conductivity type integrated into said base region, a gate insulator overlying said semiconductor layer, a gate electrode overlying said gate insulator, a drain region of said second conductivity type integrated into said semiconductor layer, and a protective element for protection against the breakdown of said gate insulator, said protective element being integrated in the same semiconductor crystal comprising said field-effect transistor and comprising a reverse connected p-n junction and a Schottky junction, said p-n junction comprising at least two semiconductor regions I, II different in conductivity type and impurity concentration, said Schottky junction being formed on said semiconductor region I forming a p-n junction, said region I having higher impurity concentration at said p-n junction than said region II forming said p-n junction, said Schottky junction and said p-n junction thereby establish means effective to suppress minority carrier injection, one of the materials forming said Schottky junction and the said region II forming said p-n junction being electrically connected to said gate electrode, the remainder being electrically connected to said source.

Claim 10

A high frequency insulated gate field-effect transistor comprising a substrate of a first conductivity type, a uniformly thin semiconductor layer of a second conductivity type overlying said substrate and higher in impurity concentration than said substrate, a base region of said first conductivity type integrated into said semiconductor layer to a depth sufficient to electrically connect it to said substrate, a source region of said second conductivity type integrated into said base region, a gate insulator overlying said semiconductor layer, a gate electrode overlying said gate insulator, a drain region of said second conductivity type integrated into said semiconductor layer, and a protective element for protection against the breakdown of said gate insulator, said protective element being integrated in the same semiconductor crystal comprising said field-effect transistor and comprising a reverse connected p-n junction and a Schottky junction, said p-n junction comprising at least two semiconductor regions I, II different in conductivity type and impurity concentration, said Schottky junction being formed on said semiconductor region I forming a p-n junction, said region I having higher impurity concentration at said p-n junction than said region II forming said p-n junction, said Schottky junction and said p-n junction thereby establish means effective to suppress minority carrier injection, one of the materials forming said Schottky junction and the said region II forming said p-n junction being electrically connected to said gate electrode, the remainder being electrically connected to said source.

Claim 11

A high frequency insulated gate field-effect transistor comprising a substrate of a first conductivity type, a uniformly thin semiconductor layer of a second conductivity type overlying said substrate and higher in impurity concentration than said substrate, a base region of said first conductivity type integrated into said semiconductor layer to a depth sufficient to electrically connect it to said substrate, a source region of said second conductivity type integrated into said base region, a gate insulator overlying said semiconductor layer, a gate electrode overlying said gate insulator, a drain region of said second conductivity type integrated into said semiconductor layer, and a protective element for protection against the breakdown of said gate insulator, said protective element being integrated in the same semiconductor crystal comprising said field-effect transistor and comprising a reverse connected p-n junction and a Schottky junction, said p-n junction comprising at least two semiconductor regions I,II different in conductivity type and impurity concentration, said Schottky junction being formed on said semiconductor region I forming a p-n junction, said region I higher in impurity concentration at said p-n junction than another said region II forming said p-n junction, said Schottky junction and said p-n junction thereby establish means effective to suppress minority carrier injection, one of the materials forming said Schottky junction and the said region II forming said p-n junction being electrically connected to said gate electrode, the remainder being said semiconductor substrate.

Claim 12

A high frequency insulated gate field-effect transistor comprising a substrate of a first conductivity type, a uniformly thin semiconductor layer of a second conductivity type overlying said substrate and higher in impurity concentration than said substrate, a base region of said first conductivity type integrated into said semiconductor layer to a depth sufficient to electrically connect it to said substrate, a source region of said second conductivity type integrated into said base region, a gate insulator overlying said semiconductor layer, a gate electrode overlying said gate insulator, a drain region of said second conductivity type integrated into said semiconductor layer, and a protective element for protection against the breakdown of said gate insulator, said protective element being integrated in the same semiconductor crystal comprising said field-effect transistor and comprising a reverse connected p-n junction and a Schottky junction, said p-n junction comprising at least two semiconductor regions I,II different in conductivity type and impurity concentration, said Schottky junction being formed on said semiconductor region I forming a p-n junction, said region I higher in impurity concentration at said p-n junction than another said region II forming said p-n junction, said Schottky junction and said p-n junction thereby establish means effective to suppress minority carrier injection, one of the materials forming said Schottky junction and the said region II forming said p-n junction being electrically connected to said gate electrode, the remainder being said semiconductor substrate.

Claim 13

A high frequency insulated gate field-effect transistor comprising a substrate of a first conductivity type, a uniformly thin semiconductor layer of a second conductivity type overlying said substrate and higher in impurity concentration than said substrate, a base region of said first conductivity type integrated into said semiconductor layer to a depth sufficient to electrically connect it to said substrate, a source region of said second conductivity type integrated into said base region, a gate insulator overlying said semiconductor layer, a gate electrode overlying said gate insulator, a drain region of said second conductivity type integrated into said semiconductor layer, and protective element for protection against the breakdown of said gate insulator, said protective element being integrated in the same semiconductor crystal comprising said field-effect transistor and comprising reverse connected two Schottky junctions, said Schottky junctions comprising two separate metal layers on a semiconductor region which is isolated from said substrate and establishing means effective to suppress minority carrier injection, one of said metal layers being electrically connected to said gate electrode, the remainder being electrically connected to said substrate or said source.

Claim 14

A high frequency insulated gate field-effect transistor comprising a substrate of a first conductivity type, a uniformly thin semiconductor layer of a second conductivity type overlying said substrate and higher in impurity concentration than said substrate, a base region of said first conductivity type integrated into said semiconductor layer to a depth sufficient to electrically connect it to said substrate, a source region of said second conductivity type integrated into said base region, a gate insulator overlying said semiconductor layer, a gate electrode overlying said gate insulator, a drain region of said second conductivity type integrated into said semiconductor layer, and protective element for protection against the breakdown of said gate insulator, said protective element being integrated in the same semiconductor crystal comprising said field-effect transistor and comprising reverse connected two Schottky junctions, said Schottky junctions comprising two separate metal layers on a semiconductor region which is isolated from said substrate and establishing means effective to suppress minority carrier injection, one of said metal layers being electrically connected to said gate electrode, the remainder being electrically connected to said substrate or said source.