A semi-elliptical oxide trench ldmos transistor

Abstract

The invention discloses a semi-elliptical oxidation trench LDMOS transistor. The buried oxide layer is located above the substrate layer; the silicon film layer is located above the buried oxide layer; the silicon film layer includes a silicon body, a source region, an oxidation trench, a drift region and a drain region ; The silicon body and the drain area are located on both sides of the top of the silicon film layer; the source area is located in the groove of the silicon body; region, silicon body, oxidation trench and all areas other than the drain region; the channel is provided by the side of the source region close to the drain region and the silicon body between the drift region; the source electrode is located above the silicon body and the source region, covering part of the silicon body and the source region; the gate oxide layer is located above the channel and completely covers the channel; the gate electrode completely covers the gate oxide layer; the extended oxide layer is located above the silicon film layer and is in close contact with the gate oxide layer; the drain electrode completely covers the drain region, and Adhere to the extended oxide layer. The breakdown voltage of the invention is significantly improved, and the quality factor of device performance is more superior.

Description

technical field [0001] The invention belongs to the field of semiconductor high-voltage power devices, in particular to a lateral double-diffused metal oxide semiconductor (Lateral Double-diffused Metal Oxide Semiconductor, LDMOS) transistor with a semi-elliptical oxidation trench. Background technique [0002] With the rapid development of semiconductor high-voltage devices, the market has higher and higher requirements for semiconductor high-voltage devices. Therefore, in order to improve the performance of the device, many technical research directions have been derived, and it is a very important topic to deal with the trade-off relationship between the breakdown voltage and the on-resistance. Generally speaking, in order to improve the performance of high-voltage LDMOS transistors, a larger breakdown voltage (Breakdown Voltage, BV) and a lower on-resistance (On-resistance, R on ). The breakdown voltage of the device is proportional to the length of its drift region. T...

AI Technical Summary

Problems solved by technology

However, the groove is rectangular, so that the current path changes from the traditional linear shape to a U shape, thereby prolonging the conduction path and increasing the on-resistance

On the other hand, the trench can adjust the electric field inside the drift region, increase the doping concentration of the drift region, so as to reduce the on-resistance

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