Physics-Based Breakdown Voltage Optimization of Trench MOS Barrier Schottky Rectifiers

作者：Latorre Rey Alvaro D^*; Mudholkar Mihir; Quddus Mohammed Tanvir

来源：IEEE Transactions on Electron Devices, 2018, 65(3): 1072-1078.

DOI：10.1109/TED.2018.2797267

• Breakdown voltage
• device optimization
• MOS devices
• Schottky rectifiers

A comprehensive study of the breakdown voltage optimization of trenchMOS barrier Schottky (TMBS) rectifiers is performed by means of drift-diffusion simulations. First, the principles of operation are explained in terms of the charge-sharing effect between the Schottky and trench MOS components of the unit cell, and correlated with the profiles of the electric field along the drift region ESch and the MOS capacitor ETMOS. Then, the systematic variation of relevant design parameters is used to determine breakdown voltage and leakage current trends, which are analyzed in terms of the electric field. Our results show that ESch is the dominating component in structures with thick oxides, shallow trenches, or high-doping concentrations, whereas ETMOS is the limiting factor for devices with thin oxides, deep trenches, or low doping. Finally, optimum BV is found when the peak value of ESch and ETMOS is approximately the same, and this condition can be reached in a wide range of trench depths for devices with long drift regions and high doping, but in a very narrow window for thin epi-layers or low-doping concentration.

• 出版日期2018-3