Design And Research Of New Type Of Soi-ldmos Structure

The Radio-Frequency power device is a very important element for wireless communication technology. The RF power LDMOS is widely used in high-gain and narrow-band for wireless communication. As a very successful RF power device, it has many advantages. But, as a RF device, its parasitic capacitance will impact many output characteristic such as power gain and make the output match more difficult. The SOI structure can solve the problem. But, the SOI device have defects, the power consumption and the rejection of heat in the active state of device are big problems. As a power device, the self-heating is more severe.So, in this paper, after the research of the structural parameter and the electricity feature, the author proposes a new structure:TG-PSOILDMOS(Trench Gate-Partial Silicon on Insulator LDMOS)In order to make the horizon channel vertical and let the distribution of current density inside the device more uniform, we take the trench gate. By using this structure, we reduce the device area and the cost. We use the Partial-SOI to supply a heat-transfer passage between the device and the substrate, make the heat elimination more convenience. In the end, we add a process step to reduce the capacitance between the gate and drain. So, we consider the effect of structural parameter about the breakdown voltage and the capacitance, then find the optimized structural parameters. The results are:we reduce 8% length of the device, increase the breakdown voltage by about 33% and take a good frequency performance.