N-TYPE LATERAL DOUBLE-DIFFUSED METAL-OXIDE-SEMICONDUCTOR FIELD-EFFECT TRANSISTOR
An N type lateral double-diffused metal oxide semiconductor field effect transistor ( 200 ) includes a substrate ( 202 ); a first N well ( 204 ) formed on the substrate; a second N well ( 206 ), a first P well ( 208 ), a third N well ( 210 ) and a fourth N well ( 212 ); a source lead-out region ( 214 ) formed on the first P well ( 208 ); a drain lead-out region ( 216 ) formed on the fourth N well ( 212 ); a first gate lead-out region formed on surfaces of the second N well ( 206 ) and the first P well ( 208 ); and a second gate lead-out region formed on surfaces of the first P well ( 208 ) and the third N well ( 210 ). The first gate lead-out region and the second gate lead-out region are respectively led out by means of metal wires, and then are connected to serve as a gate.
1 . An N type lateral double-diffused metal oxide semiconductor field effect transistor, comprising:
a substrate;
a first N well formed on the substrate;
a second N well, a first P well, a third N well, and a fourth N well, all of which are formed on a surface of the first N well; wherein the first P well is connected to the second N well and the third N well, respectively; the third N well is connected to the fourth N well;
a source lead-out region formed on the first P well;
a drain lead-out region fanned on the fourth N well;
a first gate lead-out region formed on surfaces of the second N well and the first P well; and
a second gate lead-out region formed on surfaces of the first P well and the third N well;
wherein the first gate lead-out region and the second gate lead-out region are respectively led out by means of metal wire, and the first gate lead-out region and the second gate lead-out region are connected to serve as a gate of the N type lateral double-diffused metal oxide semiconductor field effect transistor.
2 . The N type lateral double-diffused metal oxide semiconductor field effect transistor according to claim 1 , wherein a doping concentration of the fourth N well is greater than a doping concentration of the third N well.
3 . The N type lateral double-diffused metal oxide semiconductor field effect transistor according to claim 1 , further comprising:
a first field oxide layer formed on a surface of the second N well; and
a second field oxide layer formed on a surface of the third N well and extending to a surface of the fourth N well.
4 . The N type lateral double-diffused metal oxide semiconductor field effect transistor according to claim 3 , wherein the first field oxide layer and the second field oxide layer are made of silicon nitride.
5 . The N type lateral double-diffused metal oxide semiconductor field effect transistor according to claim 4 , wherein the first gate lead-out region comprises:
a gate oxide layer fanned on a surface of the second N well and extending to a surface of the first P well, and
a polycrystalline silicon gate on surfaces of the gate oxide layer and the first field oxide layer;
wherein the second gate lead-out region comprises:
a gate oxide layer formed on a surface of the first P well and extending to a surface of the third N well; and
a polycrystalline silicon gate on surfaces of the gate oxide layer and the second field oxide layer.
6 . The N type lateral double-diffused metal oxide semiconductor field effect transistor according to claim 4 , further comprising:
a second P well formed on a surface of the substrate and connected to the second N well;
a substrate lead-out region located on the second P well; and
a third field oxide layer formed on a surface of the second P well; wherein the first field oxide layer extends to a surface of the second P well.
7 . The N type lateral double-diffused metal oxide semiconductor field effect transistor according to claim 6 , wherein the substrate lead-out region is a P type lead-out region.
8 . The N type lateral double-diffused metal oxide semiconductor field effect transistor according to claim 1 , wherein the drain lead-out region is an N type lead-out region.
9 . The N type lateral double-diffused metal oxide semiconductor field effect transistor according to claim 1 , wherein the source lead-out region comprises a first N type lead-out region, a second N type lead-out region, and a P type lead-out region; the first N type lead-out region and the second N type lead-out region are located on opposite sides of the P type lead-out region.
10 . The N type lateral double-diffused metal oxide semiconductor field effect transistor according to claim 1 , wherein the substrate is a P type substrate.