Method of fabricating a lateral double-diffused MOSFET (LDMOS) transistor
First Claim
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1. A method of fabricating a transistor having a source region, a drain region and a gate region on a substrate, the method comprising:
- implanting, into a surface of the substrate, a high voltage (HV) n-doped n-well with a first volume and a first surface area;
forming a gate oxide between a source region and a drain region of the transistor;
implanting, into the source region of the transistor, a p-doped p-body with a second volume and a second surface area after forming the gate oxide;
covering the gate oxide with a conductive material;
forming a source-side oxide spacer and a drain-side oxide spacer on sidewalls of the gate oxide;
implanting, into the source region of the transistor, a n-doped n+ region with a third volume and a third surface area and a p-doped p+ region with a fourth volume and a fourth surface area;
implanting, into the drain region of the transistor, a n-doped n+ region with a fifth volume and a fifth surface area; and
implanting, into the drain region of the transistor, a n-doped lightly doped drain that is shallower than the n-doped n+ region and having a portion which extends beneath the drain-side oxide spacer, the n-doped lightly doped drain having a sixth volume and a sixth surface area.
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Abstract
A method of monolithically fabricating a lateral double-diffused MOSFET (LDMOS) transistor having a source, drain, and a gate on a substrate, with a process flow that is compatible with a CMOS process flow, is disclosed.
191 Citations
41 Claims
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1. A method of fabricating a transistor having a source region, a drain region and a gate region on a substrate, the method comprising:
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implanting, into a surface of the substrate, a high voltage (HV) n-doped n-well with a first volume and a first surface area; forming a gate oxide between a source region and a drain region of the transistor; implanting, into the source region of the transistor, a p-doped p-body with a second volume and a second surface area after forming the gate oxide; covering the gate oxide with a conductive material; forming a source-side oxide spacer and a drain-side oxide spacer on sidewalls of the gate oxide; implanting, into the source region of the transistor, a n-doped n+ region with a third volume and a third surface area and a p-doped p+ region with a fourth volume and a fourth surface area; implanting, into the drain region of the transistor, a n-doped n+ region with a fifth volume and a fifth surface area; and implanting, into the drain region of the transistor, a n-doped lightly doped drain that is shallower than the n-doped n+ region and having a portion which extends beneath the drain-side oxide spacer, the n-doped lightly doped drain having a sixth volume and a sixth surface area. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method of fabricating a semiconductor device comprising:
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forming a first transistor including; implanting, into a first surface of the substrate, a first impurity region with a first volume and a first surface area, the first impurity region being of a first type; forming a first gate oxide between a source region and a drain region of the first transistor prior to implanting a second impurity region; implanting, into the source region of the first transistor, the second impurity region with a second volume and a second surface area after forming the first gate oxide, the second impurity region being of an opposite second type relative to the first type; covering the first gate oxide with a first conductive material; forming a source-side oxide spacer and a drain-side oxide spacer on sidewalls of the first gate oxide; implanting, into the source region of the transistor, a third impurity region with a third volume and a third surface area and a fourth impurity region with a fourth volume and a fourth surface area, the third impurity region being of the first type, the fourth impurity region being of the opposite second type; implanting, into the drain region of the first transistor, a fifth impurity region with a fifth volume and a fifth surface area, the fifth impurity region being of the first type; and implanting, into the drain region of the first transistor, a sixth impurity region with a sixth volume that is shallower than the fifth volume and a sixth surface area, the sixth impurity region being implanted with a spacing from the second impurity region and having a portion which extends beneath the drain-side oxide spacer, the sixth impurity region being of the first type. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40)
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41. A method of fabricating a transistor having a source region, a drain region and a gate region on a substrate, the method comprising:
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implanting, into a surface of the substrate, a first impurity region with a first volume and a first surface area, the first impurity region being of a first type; implanting, into the source region of the transistor, a second impurity region with a second volume and a second surface area, the second impurity region being of an opposite second type relative to the first type; forming a gate oxide between the source region and the drain region of the transistor prior to implanting the second impurity region; covering the gate oxide with a conductive material; implanting, into the source region of the transistor, a third impurity region with a third volume and a third surface area and a fourth impurity region with a fourth volume and a fourth surface area, the third impurity region being of the first type, the fourth impurity region being of the opposite second type; implanting, into the drain region of the transistor, a fifth impurity region with a fifth volume and a fifth surface area, the fifth impurity region being of the first type; and implanting, into the drain region of the transistor, a plurality of sixth impurity regions each having a sixth volume and a sixth surface area, and is distanced apart from other sixth impurity regions along the first surface of the substrate, the sixth impurity region closest to the gate oxide being implanted with a spacing from the second impurity region, each sixth impurity region being of the first type.
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Specification