Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
310 words
An insulated-gate field-effect transistor comprising a semiconductor body having a surface-adjacent source region of one conductivity type which is surrounded in the body by a surface-adjacent second region of the opposite conductivity type, a third region adjoining the second region and having a lower conductivity type determining doping concentration, at least a part of said second and third regions being located in a main current path from the source region to a drain of the transistor, a conductive layer being present on an insulating layer on said part of at least the second region to form an insulated gate of the transistor for capacitively controlling in said part a conductive channel in the main current path between the source region and the drain, a surface-adjacent emitter region of said one conductivity type also being surrounded in the body by the second region, said emitter region being located at a side of the source region remote from the channel part of the second region and being separated from the source region by an intermediate part of the second region, the source region being electrically connected to said intermediate part, and a resistive current path in the second region being present below the emitter region, characterised in that said resistive current path extends from said intermediate part to a further part of the second region which is electrically connected to the emitter region, in that a source electrode is electrically connected to said further part of the second region so as to be electrically connected via said resistive current path to the source region, and in that the emitter region serves to modulate the conductivity of the third region by charge-carrier injection from said intermediate part of the second region when the source-drain current along the resistive current path is sufficient to forward-bias said intermediate part with respect to the third region.
Claim 2
Dependent Claim
310 words
An insulated-gate field-effect transistor comprising a semiconductor body having a surface-adjacent source region of one conductivity type which is surrounded in the body by a surface-adjacent second region of the opposite conductivity type, a third region adjoining the second region and having a lower conductivity type determining doping concentration, at least a part of said second and third regions being located in a main current path from the source region to a drain of the transistor, a conductive layer being present on an insulating layer on said part of at least the second region to form an insulated gate of the transistor for capacitively controlling in said part a conductive channel in the main current path between the source region and the drain, a surface-adjacent emitter region of said one conductivity type also being surrounded in the body by the second region, said emitter region being located at a side of the source region remote from the channel part of the second region and being separated from the source region by an intermediate part of the second region, the source region being electrically connected to said intermediate part, and a resistive current path in the second region being present below the emitter region, characterised in that said resistive current path extends from said intermediate part to a further part of the second region which is electrically connected to the emitter region, in that a source electrode is electrically connected to said further part of the second region so as to be electrically connected via said resistive current path to the source region, and in that the emitter region serves to modulate the conductivity of the third region by charge-carrier injection from said intermediate part of the second region when the source-drain current along the resistive current path is sufficient to forward-bias said intermediate part with respect to the third region.
Claim 3
Dependent Claim
36 words
A transistor as claimed in Claim 1, further characterised in that said further part of the second region is laterally surrounded by the emitter region which is laterally surrounded in the-second region by the source region.
Claim 4
Dependent Claim
52 words
A transistor as claimed in Claim 1 or Claim 2, further characterised in that the further part of the second region is electrically connected to the emitter region by a short-circuiting conductive layer at an edge of the E-n junction between the emitter region and said further part of the second region.
Claim 5
Dependent Claim
52 words
A transistor as claimed in anyone of the preceding Claims, further characterised in that the source region is electrically connected to said intermediate part of the second region by a short-circuiting conductive layer at an edge of the p-n junction between the source region and said intermediate part of the second region.
Claim 6
Dependent Claim
36 words
A transistor as claimed in Claim 3 or Claim 4, further characterised in that the semiconductor body is of silicon, and a metal-silicide region formed at the body surface provides said short-circuiting conductive layer or layers.
Claim 7
Dependent Claim
33 words
A transistor as claimed in Claim 5, further characterised in that the conductive layer forming the gate of the transistor comprises the same metal-silicide as said region which provides said short-circuiting conductive layer.
Claim 8
Dependent Claim
26 words
A transistor as claimed in anyone of the preceding Claims, further characterised in that emitter and source regions have substantially the same doping concentration and thickness.
Claim 9
Dependent Claim
74 words
A transistor as claimed in anyone of the preceding Claims, further characterised in that the emitter and source regions and the second region adjoin one major surface of the semiconductor body, in that said third region is a low-doped region of said one conductivity type, and in that a drain region which is more highly doped than the third region is present between the third region and the opposite major surface of the body.
Claim 10
Dependent Claim
31 words
A transistor as claimed in Claim 8, further characterised in that the insulated gate is present on a part of the second region at said one major surface of the body.