Lateral diffused metal oxide semiconductor field effect transistor
An LDMOS includes a body region disposed in the substrate and having a first conductivity type; a drift region disposed in the substrate and having a second conductivity type; a source region disposed in the body region and having the second conductivity type; a drain region disposed in the drift region and having the second conductivity type; an isolation region disposed in the drift region between the source region and the drain region; a gate disposed on the body region and the drift region; a source field plate electrically connected to the source region; a drain field plate electrically connected to the drain region; and a first gate plate electrically connected to the gate. The first gate plate is correspondingly disposed above the gate. The shapes of the first gate plate and the gate are substantially the same when viewed from a top view.
1. A lateral diffused metal oxide semiconductor (LDMOS), comprising:
a body region disposed in a substrate, and the body region has a first conductivity type;
a drift region disposed in the substrate, and the drift region has a second conductivity type opposite to the first conductivity type;
a source region disposed in the body region, and the source region has the second conductivity type;
a drain region disposed in the drift region, and the drain region has the second conductivity type;
an isolation region disposed in the drift region between the source region and the drain region, wherein the isolation region is field oxide, local oxidation of silicon, or shallow trench isolation;
a gate disposed on the body region and the drift region;
a source field plate electrically connected to the source region;
a drain field plate electrically connected to the drain region; and
a first gate plate electrically connected to the gate through an interlayer dielectric layer over the gate, wherein the first gate plate is disposed laterally between two portions of the source field plate;
wherein the first gate plate is correspondingly disposed above the gate, and a shape of the first gate plate and the gate are substantially the same from a top view.
2. The lateral diffused metal oxide semiconductor as claimed in claim 1 , further comprising:
a bulk region disposed in the body region and adjacent the source region, and the bulk region has the first conductivity type;
wherein the bulk region is electrically connected to the source field plate.
3. The lateral diffused metal oxide semiconductor as claimed in claim 1 , wherein the first gate plate and the gate are electrically connected in parallel.
4. The lateral diffused metal oxide semiconductor as claimed in claim 1 , wherein the shape of the first gate plate and the gate are completely the same from a top view.
5. The lateral diffused metal oxide semiconductor as claimed in claim 1 , wherein the source field plate and the first gate plate are patterned from the same metallization layer.
6. The lateral diffused metal oxide semiconductor as claimed in claim 1 , wherein a length of the first gate plate is shorter than a length of the gate.
7. The lateral diffused metal oxide semiconductor as claimed in claim 1 , wherein a length of the first gate plate is longer than or equal to a length of the gate.
8. The lateral diffused metal oxide semiconductor as claimed in claim 1 , wherein the shape is a multi-finger, an ellipse, or a circle.
9. The lateral diffused metal oxide semiconductor as claimed in claim 1 , wherein the gate has a width of between 5000 μm and 20000 μm.
10. The lateral diffused metal oxide semiconductor as claimed in claim 1 , wherein the lateral diffused metal oxide semiconductor operates at a frequency of between 1 MHz and 100 MHz.
11. The lateral diffused metal oxide semiconductor as claimed in claim 1 , further comprising:
a second gate plate electrically connected to the first gate plate;
wherein the second gate plate is disposed in a metallization layer above the first gate plate.
12. The lateral diffused metal oxide semiconductor as claimed in claim 11 , wherein the second gate plate is correspondingly disposed above the gate, and a shape of the second gate plate and the gate are substantially the same from a top view.