Research And Design Of Low Specific On-Resistance Of Lateral Super-Junction Devices

Because superjunction devices have outstanding advantages in alleviating the contradiction between device breakdown voltage?V_B?and specific on-resistance(R_on·sp),they have received many research and experiments.The theory known as"milestone"must be the relationship of R_on·sp?V_B^1.32 among them,this theory breaks the"silicon limit"relationship of the traditional R_on·sp?V_B^2.5 in vertical device,which reduces the square relationship between the specific on-resistance of the device and the breakdown voltage to a nearly linear relationship.With the continuous research on super-junction devices,it has been shown that super-junction devices working in Non-full depletion?NFD?mode have lower specific on-resistance according to the latest paper,and the minimum specific on-resistance R_on·min can be found in this mode.But so far it has only stayed in the theoretical stage,and there is no paper about experimental verification.In this paper,the Equivalent Substrate?ES?model is used as the theoretical and design guide to eliminate the SAD?Substrate Assisted Depletion?effect of lateral super-junction devices.Furthermmore,we have made preliminary preparations for obtaining the lowest specific on-resistance R_on·min of the superjunction device experimrntally and the correctness of the optimal concentration formula for a given superjunction length and strip width is verified.The main work and innovations are as follows:Firstly,the analysis of the charge field and potential field of the superjunction device shows that as the superjunction concentration increases,the device's withstand voltage V_B and specific on-resistance R_on·sp will decrease under the conditions of fixed superjunction width and superjunction length,so the figure of merit f_? is defined to help observe its changing trend,The equivalence relationship between the highest figure of merit f_? and the minimum specific on-resistance was obtained through the change rule of figure of merit,and the proof was given.The optimized concentration of the SJ corresponding to the highest figure of merit was mathematically quantified and the design formula was given N_OP=exp(38.42W_SJ^-0.034L_SJ^0.0011).The simulation verifies the change trend of the figure of merit F_OM and the accuracy of the design formula.In order to eliminate the influence of the channel resistance and contact resistance on the deviation caused by the theoretical matching,a new method for testing the net resistance in the super junction region of super junction devices is proposed.From the material,device structure and mathematically,the correctness of this test method is demonstrated.Secondly,the full coverage of the full-depletion mode to the non-full depletion mode of SJ devices are achieved through the calculation and range biasing of the injected dose of the SJ region.This experimental results are compared with the traditional Triple Resurf theoretical values and the published results of the lateral super-junction experiment,it is found that the lateral super-junction device of this experiment has better characteristics than the on-resistance under the same voltage level.According to the analysis of the measured data,the accuracy and correctness of the most concentrated formula are verified.