功率二極體製程與模擬最佳化

Abstract

摘 要 在本篇論文中，我們將研究快速恢復二極體和蕭特基能障二極體等功率二極體。快速恢復二極體常用在切換式電源供應器及汽車控制電路等地方。另外，蕭特基能障二極體則常用在低壓、高頻整流器及個人電腦主機板中的整流二極體。 功率元件有一個獨一無二的特性，那就是它們的高耐壓能力。但是在應用上，圓柱型（cylindrical）和球型（spherical）接面崩潰限制了操作時的崩潰電壓，使其往往遠低於理想狀況下的情形。高壓接面結構，例如場限環（Field Limiting Ring）、場板（field plate）和補償式場板及場限環（offset multiple field plate and field limiting ring）已經被廣泛地應用於高壓元件上。二維數值模擬的發展使我們對終端終結結構的設計結果有高度的信心。在這邊，我們使用製程模擬軟體SILVACO來做高壓元件邊緣接面結構的設計。 我們將有著接面終結結構的快速恢復二極體和蕭特基能障二極體付諸實做，去印證終端技術的保護效果。靠著補償式場板及場限環良好設計和正確的實驗流程，我們可以達成600伏特的快速恢復二極體的製作。同樣的，靠著保護環的保護，30伏特的蕭特基能障二極體也可以實現。在這邊，我們使用白金（Pt）來形成所需的蕭特基能障。

Abstract In this thesis, fast recovery rectifiers and Schottky barrier rectifiers are investigated. Fast recovery rectifiers are used in switching mode power supplies (SMPS), and motor control circuits, etc. Besides, Schottky barrier rectifiers are commonly used as low voltage, high frequency rectifiers and diodes in PC motherboard. A unique and distinguishing feature of power devices is their high voltage blocking capacity. In application, however, cylindrical and spherical junction breakdowns constrain the breakdown voltage and cause it to be lower than the ideal case. Junction termination structures of Field Limiting Ring (FLR), Field Plate (FP), and Offset Multiple Field Plate and Field Limiting Ring (OFP-FLR) had been extensively used in the high voltage devices. The development of two-dimensional numerical simulation techniques now allows the design of edge termination with a high degree of confidence. The process simulator, SILVACO, is adopted to design the edge termination structures of high voltage devices. Fast recovery rectifier and Schottky barrier rectifier with junction termination structures are fabricated to verify the protection effect of termination technologies. The 600V fast recovery rectifier can be achieved by means of the optimal design of OFP-FLR structure and precise experimental procedures. The 30V Schottky rectifier can also be completed with the use of guard ring protection. Platinum is adopted here to form the Schottky barrier.