Design And Manufacture Of High Power Switching Transistor

The research purpose of this thesis is based on a typical large power transistor’sdesigning and manufacturing. Discussing how to improve the power-switchingtransistor’s dissipation power and reduce its switching time. Moreover, we use theproduct’s layout and process’ improvements to achieve the product’s parametersrequirements.The paper introduces the current development of high power switching transistor.Then deeply analysis how to improve the product’s power dissipation and reduces theswitching time of the transistor. Discussing the different of the chip structure andprocess to improve the dissipation power, switch time and frequency characteristic ofthe transistor in detail. When we design the chip structure, we increase the ratio ofemitter perimeter and area in order to improve chip usage. Improve base dopingconcentration, shorten the base width, reducing the collecting zone resistivity andthickness is an effective method to increase dissipation power or characteristicfrequency. However, the product’s dissipation power, characteristic frequency,switching time and amplitude magnification coefficient are mutually influence eachother. In considering improving a parameter, we must consider the influences of theother parameters at the same time. In addition, we need an actual tape out to determinethe process parameters.In this paper, we use the emitter with opening comb structure layout to improve therate of chips’ usage. Therefore, the products in the smaller chip area can get largeremitter perimeter. The emitter perimeter area ratio, junction capacitance are increased.The product’s dissipation power is improved and reduced the transistor’s switching time.At first, we ensure the product’s power and breakdown voltage, and then we use twicediffusion of light and strong concentration at the base region. On one hand, we canreduce the product’s saturation voltage; on the other hand, in the base region can get aconcentration gradient, using modified concentration gradient generated by the electricfield, the product’s carrier is been speed up to improve product characteristic frequency and switching time. Through the reasonable design and select a suitable manufacturingprocess, we eventually achieve the product’s requirement of electrical parameters. Wealso compare the different chip structure and process, compare it how to affect product’spower and frequency. All the things we did can help us to design similar products in areference.