High breakdown voltage MOS type semiconductor apparatus

A MOS type semiconductor device, comprising:

• a first main surface and a second main surface which face in opposite directions;
• a first conductivity type drift layer having a high resistivity;
• a second conductivity type base region formed in a surface layer of said first conductivity type drift layer on the side of said first main surface;
• a first conductivity type source region that is spaced from said first conductivity type drift layer by said second conductivity type base region;
• a gate electrode layer formed on a gate insulating film over a surface of said second conductivity type base region interposed between said first conductivity type source region and said first conductivity type drift layer;
• a source electrode formed in contact with both of said first conductivity type source region and said second conductivity type bases region;
• a second conductivity type drain layer formed on a surface of said first conductivity type drift layer on the side of said second main surface;
• a drain electrode formed on said second main surface in contact with a surface of said second conductivity type drain layer;
• and
• a gate electrode formed in contact with said gate electrode layer;
• wherein a ballast resistance layer is provided between said first conductivity type drift layer and said second conductivity type drain layer, said ballast resistance layer including a portion having a resistivity in a range of 0.05 to 1 Ω·cm and a thickness in a range of about 30 μm to 80 μm;
• and
• wherein said ballast resistance layer comprises a first conductivity type portion that contacts with said first conductivity type drift layer, and a second conductivity type portion that contact with said second conductivity type drain layer.

A MOS type semiconductor apparatus, comprising a first MOS type semiconductor device through which first current flows, and a second MOS type semiconductor device through which second current that is smaller than the first current flows, said first MOS type semiconductor device and said second MOS type semiconductor device having substantially the same structure and being provided on the same semiconductor substrate, each of the first and second MOS type conductive devices comprising:

• first main surface and second main surface which face in opposite directions;
• a first conductivity type drift layer having a high resistivity;
• a second conductivity type base region formed in a surface layer of said first conductivity type drift layer on the side of said first main surface;
• a first conductivity type source region that is spaced from said first conductivity type drift layer by said second conductivity type base region;
• a gate electrode layer formed on a gate insulating film over a surface of said second conductivity type base region interposed between said first conductivity type source region and said first conductivity type drift layer;
• a source electrode formed in contact with both of said first conductivity type source region and said second conductivity type base region;
• a second conductivity type drain layer formed on a surface of said first conductivity type drift layer on the side of said second main surface;
• a drain electrode electrically connected to said second conductivity type drain layer;
• and
• a gate electrode formed in contact with said gate electrode layer,
• wherein a ballast resistance layer is provided between said first conductivity type drift layer and said second conductivity type drain layer, said ballast resistance layer including a portion having a resistivity in a range of 0.05 to 1 Ω·cm and a thickness in a range of about 30 μm to 80 μm.

A MOS type semiconductor apparatus, comprising a first MOS type semiconductor device through which first current flows, and a second MOS type semiconductor device through which second current that is smaller than the first current flows, said first MOS type semiconductor device and said second MOS type semiconductor device having substantially the same structure and being provided on the same semiconductor substrate, each of the first and second MOS type conductive devices comprising:

• first main surface and second main surface which face in opposite directions;
• a first conductivity type drift layer having a high resistivity;
• a second conductivity type base region formed in a surface layer of said first conductivity type drift layer on the side of said first main surface;
• a first conductivity type source region that is spaced from said first conductivity type drift layer by said second conductivity type base region;
• a gate electrode layer formed on a gate insulating film over a surface of said second conductivity type base region interposed between said first conductivity type source region and said first conductivity type drift layer;
• a source electrode formed in contact with both of said first conductivity type source region and said second conductivity type base region;
• a second conductivity type drain layer formed on a surface of said first conductivity type drift layer on the side of said second main surface;
• a drain electrode formed on said second main surface in contact with a surface of said second conductivity type drain layer;
• and
• a gate electrode formed in contact with said gate electrode layer,
• wherein a ballast resistance layer is provided between said first conductivity type drift layer and said second conductivity type drain layer, said ballast resistance layer including a portion having a resistivity in a range of 0.05 to 1 Ω·cm and a thickness in a range of about 30 μm to 80 μm;
• and
• wherein said ballast resistance layer comprises a first conductivity type portion that contacts with said first conductivity type drift layer, and a second conductivity type portion that contact with said second conductivity type drain layer.

A MOS type semiconductor device, comprising:

• first main surface and second main surface which face in opposite directions;
• a first conductivity type drift layer having a high resistivity;
• a second conductivity type base region formed in a surface layer of said first conductivity type drift layer on the side of said first main surface;
• a first conductivity type source region that is spaced from said first conductivity type drift layer by said second conductivity type base region;
• a gate electrode layer formed on a gate insulating film over a surface of said second conductivity type base region interposed between said first conductivity type source region and said first conductivity type drift layer;
• a source electrode formed in contact with both of said first conductivity type source region and said second conductivity type base region;
• a first conductivity type drain layer formed on a surface of said first conductivity type drift layer on the side of said second main surface, said first conductivity type drain layer having a smaller resistivity than said first conductivity type drift layer;
• a drain electrode electrically connected to said first conductivity type drain layer;
• and
• a gate electrode formed in contact with said gate electrode layer,
• wherein a first conductivity type ballast resistance layer is provided between said first conductivity type drift layer and said first conductivity type drain layer, said ballast resistance layer providing a region that will not be depleted when avalanche breakdown occurs upon application of a high voltage to the MOS type semiconductor device that is placed in an OFF state, said ballast resistance layer having a resistivity that is substantially equal to or smaller than that of said first conductivity type drift layer, and larger than one-tenth of that of the first conductivity type drift layer, and a thickness that is at least about 1 μm.

A MOS type semiconductor apparatus, comprising a first MOS type semiconductor device through which first current flows, and a second MOS type semiconductor device through which second current that is smaller than the first current flows, said first MOS type semiconductor device and said second MOS type semiconductor device having substantially the same structure and being provided on the same semiconductor substrate, each of the first and second MOS type conductive devices comprising:

• first main surface and second main surface which face in opposite directions;
• a first conductivity type drift layer having a high resistivity;
• a second conductivity type base region formed in a surface layer of said first conductivity type drift layer on the side of said first main surface;
• a first conductivity type source region that is spaced from said first conductivity type drift layer by said second conductivity type base region;
• a gate electrode layer formed on a gate insulating film over a surface of said second conductivity type base region interposed between said first conductivity type source region and said first conductivity type drift layer;
• a source electrode formed in contact with both of said first conductivity type source region and said second conductivity type base region;
• a first conductivity type drain layer formed on a surface of said first conductivity type drift layer on the side of said second main surface, said first conductivity type drain layer having a smaller resistivity than said first conductivity type drift layer;
• a drain electrode electrically connected to said first conductivity type drain layer;
• and
• a gate electrode formed in contact with said gate electrode layer,
• wherein a first conductivity type ballast resistance layer is provided between said first conductivity type drift layer and said first conductivity type drain layer, said ballast resistance layer providing a region that will not be depleted when avalanche breakdown occurs upon application of a high voltage to the MOS type semiconductor device that is placed in an OFF state, said ballast resistance layer having a resistivity that is substantially equal to or smaller than that of said first conductivity type drift layer, and larger than one-tenth of that of the first conductivity type drift layer, and a thickness that is at least about 1 μm.

A MOS type semiconductor apparatus, comprising a first MOS type semiconductor device through which first current flows, and a second MOS type semiconductor device through which second current that is smaller than the first current flows, said first MOS type semiconductor device and said second MOS type semiconductor device having substantially the same structure and being provided on the same semiconductor substrate, each of the first and second MOS type conductive devices comprising:

• first main surface and second main surface which face in opposite directions;
• a first conductivity type drift layer having a high resistivity;
• a second conductivity type base region formed in a surface layer of said first conductivity type drift layer on the side of said first main surface;
• a first conductivity type source region that is spaced from said first conductivity type drift layer by said second conductivity type base region;
• a trench formed in said first conductivity type drift layer such that said first conductivity type source region is exposed to an inner wall of the trench, said trench having a larger depth than said second conductivity type base region;
• a gate electrode layer formed in said trench with a gate insulating film filling a space between the gate electrode layer and the inner wall of the trench;
• a source electrode formed in contact with both of said first conductivity type source region and said second conductivity type base region;
• a second conductivity type drain layer formed on a surface of said first conductivity type drift layer on the side of said second main surface;
• a drain electrode electrically connected to said second conductivity type drain layer;
• and
• a gate electrode formed in contact with said gate electrode layer,
• wherein a thick field insulating film is disposed on said first main surface at least between said first MOS type semiconductor device and said second MOS type semiconductor device.

A MOS type semiconductor apparatus, comprising a first MOS type semiconductor device through which first current flows, and a second MOS type semiconductor device through which second current that is smaller than the first current flows, said first MOS type semiconductor device and said second MOS type semiconductor device having substantially the same structure and being provided on the same semiconductor substrate, each of the first and second MOS type conductive devices comprising:

• first main surface and second main surface which face in opposite directions;
• a first conductivity type drift layer having a high resistivity;
• a second conductivity type base region formed in a surface layer of said first conductivity type drift layer on the side of said first main surface;
• a first conductivity type source region that is spaced from said first conductivity type drift layer by said second conductivity type base region;
• a trench formed in said first conductivity type drift layer such that said first conductivity type source region is exposed to an inner wall of the trench, said trench having a larger depth than said second conductivity type base region;
• a gate electrode layer formed in said trench with a gate insulating film filling a space between the gate electrode layer and the inner wall of the trench;
• a source electrode formed in contact with both of said first conductivity type source region and said second conductivity type base region;
• a first conductivity type drain layer formed on a surface of said first conductivity type drift layer on the side of said second main surface, said first conductivity type drain layer having a smaller resistivity than said first conductivity type drift layer;
• a drain electrode electrically connected to said first conductivity type drain layer;
• and
• a gate electrode formed in contact with said gate electrode layer;
• wherein a thick field insulating film is disposed on said first main surface at least between said first MOS type semiconductor device and said second MOS type semiconductor device.