MOS transistor device
First Claim
1. A trench transistor device having an upper region and a lower region, comprising:
- a gate trench extending through the upper region and the lower region;
a gate electrode projecting into the gate trench, insulated via an outer gate oxide, the gate electrode having a gate step beginning at a transition from the upper region to the lower region; and
a mesa region adjacent the gate trench, having a body reinforcement extending through a portion of the upper region, through the transition at a depth below a beginning of the gate step.
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Accused Products
Abstract
The invention relates to a MOS transistor device of the trench type, in which, in a semiconductor region of a first conductivity type, within a deep gate trench extending in the vertical direction of the semiconductor region, a vertical gate electrode and a gate oxide with a field plate step insulating the latter are formed and, in an adjoining mesa region outside and laterally with respect to the deep trench, at the upper section thereof, a source electrode region of the first conductivity type and a body region of a second conductivity type with one or a plurality of assigned body contact are formed, a drain electrode region of the first conductivity type lying opposite the deep trench in the vertical direction. The MOS transistor has a deep body reinforcement of the second conductivity type below the body region at the location of the body contact, said body reinforcement lying deeper than the field plate step.
12 Citations
24 Claims
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1. A trench transistor device having an upper region and a lower region, comprising:
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a gate trench extending through the upper region and the lower region;
a gate electrode projecting into the gate trench, insulated via an outer gate oxide, the gate electrode having a gate step beginning at a transition from the upper region to the lower region; and
a mesa region adjacent the gate trench, having a body reinforcement extending through a portion of the upper region, through the transition at a depth below a beginning of the gate step. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A trench transistor device having an upper region and a lower region, comprising:
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a gate trench extending through the upper region and the lower region;
a gate electrode projecting into the gate trench, insulated via an outer gate oxide;
the gate electrode having a gate step beginning at a transition from the upper region to the lower region;
a mesa region adjacent the gate trench; and
body reinforcement means located in the mesa region, extending through a portion of the upper region, through the transition at a depth below a beginning of the gate step
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14. A MOS transistor device of the trench type comprising:
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a semiconductor region of a first conductivity type, within a deep gate trench extending in the vertical direction of the semiconductor region, a vertical gate electrode and a gate oxide insulating the latter are formed and, in an adjoining mesa region outside and laterally with respect to the gate trench, at the upper section thereof, a source electrode region of the first conductivity type and a body region of a second conductivity type with one or a plurality of assigned body contacts are formed;
the gate oxide being thinned in the upper section and undergoing transition via a field plate step to a thickened section situated in the lower section of the gate trench, and a drain electrode region of the first conductivity type lying opposite the gate trench in the vertical direction and the MOS transistor device comprising a multiplicity of vertical MOS transistors, a gate trench and a mesa region always being formed successively in a manner alternating in the lateral direction, which is perpendicular to the vertical direction, and each mesa region being a dense trench mesa region which, in particular with respect to an adjacent MOS transistor, has a width that is less than 2.5 times the maximum thickness of the gate oxide in the associated gate trench; and
wherein the MOS transistor device furthermore has a deep body reinforcement of the second conductivity type, which is provided below the body region at the location of the body contact and reaches into the depth of the semiconductor region at least as far as the field plate step of the gate oxide or deeper. - View Dependent Claims (15, 16, 17, 18, 19)
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20. A MOS transistor device of the trench type comprising:
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a semiconductor region of a first conductivity type, within a deep gate trench extending in the vertical direction of the semiconductor region, a vertical gate electrode and a gate oxide insulating the latter are formed and, in an adjoining mesa region outside and laterally with respect to the gate trench, at the upper section thereof, a source electrode region of the first conductivity type and a body region of a second conductivity type with one or a plurality of assigned body contacts are formed;
the gate oxide being thinned in the upper section and undergoing transition via a field plate step to a thickened section situated in the lower section of the gate trench, and a drain electrode region of the first conductivity type lying opposite the gate trench in the vertical direction and the MOS transistor device comprising a multiplicity of vertical MOS transistors, a gate trench and a mesa region always being formed successively in a manner alternating in the lateral direction, which is perpendicular to the vertical direction, and each mesa region being a dense trench mesa region which, in particular with respect to an adjacent MOS transistor, has a width that is less than 2.5 times the maximum thickness of the gate oxide in the associated gate trench; and
wherein the MOS transistor device furthermore has a deep body reinforcement of the second conductivity type, which is provided below the body region at the location of the body contact and reaches into the depth of the semiconductor region at least as far as the field plate step of the gate oxide or deeper, wherein the deep body reinforcement is formed by one or a plurality of staggered implantation. - View Dependent Claims (21, 22, 23, 24)
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Specification