Design & Fabrication Of The Insulated Gate Bipolar Transistor(IGBT)

The application of IGBT has been expanded since the invention from 80's of last century. As the latest generation of composite full-controlled power devices, IGBT has most outstanding characteristics, such as voltage control, large input impedance, small driving power, simple control circuit, low switching losses, and high operating frequency. Among them, the role of 1700 V IGBT played in the motor control, new energy, rail transportation, smart grid, electric vehicles and other fields is irreplaceable. However, due to the relative backwardness of domestic technological level, the design and production of high voltage IGBTs are lagging behind abroad. This paper aims to combine the existing domestic technology, research, and develop 1700 V/100 A IGBT with independent intellectual property rights, on the other hand, a new structure applied for 3300 V IGBT is also put forward.The main work and innovations include:1. This paper is based on the work of Dr. Zhang Bin, which is to improve the 1700 V IGBT chip. According to the breaking down voltage of the chip is low (test value is 1700 V), the resistivity of the material is increased, then the optimum process of P+well is determined by the bias test. According to the saturation voltage drop is high (3.7V), the area of layout is increased meanwhile the bias test of the backside laser annealing process is also done. The test data is shown as BV= 1890 V, Ic= 100 A, VCE(sat)= 2.8 V, Vth= 4.75 V, Iges< 15 nA, Toff= 1.14 ?s, Eoff< 30 mJ. The key characteristics of the IGBT improved significantly except the Toff is longer than the design target.2. A new IGBT structure with double N+residual layer which was put forward by Dr. Zhang Bin is applied to 1700 V IGBT. The simulation result shows that the JFET resistance is improved by this structure. However, the test value of breaking down voltage is just around 1300 V. A research is done to discuss the significant difference between the simulation and test. The conclusion is achieved through the defect corrosion test for many times, because the triple diffusion process needs high temperature (1285?) and long time (168 hrs), it results that the defect density is too large, which is the major cause of premature breakdown.3?The new structure with double N+ diffusion residual layer is applied to 3300 V IGBT which based on the work of the 2nd point. Because a double-sided N+ diffusion layer of the 3300 V IGBT required smaller junction depth, the diffusion time is shorter, which means it can avoid the risk in process so as to exert the advantages of the structure. Then the device has a better trade off between the breakdown voltage and conduction voltage drop. Under this premise, this paper complete the work of 3300V IGBT as the material selection, cell and field limiting ring structure, the process parameters. Becausethe time is not enough, the verification work needs to be completed for future generations.