近年來，部份消費性與可攜性的電子裝置變得相當重要與熱門。例如：MP3隨身聽、大哥大與液晶顯示器等。在這些產品中，功率元件扮演重要角色。功率元件必須擔負兩大責任，一為承受高工作電壓，另一為具有較小的導通電阻。
RESURF LDMOSFET為其中一種功率IC，其I-V特性及製程與一般MOSFET相同，容易被整合於其他元件之中。P-ring LDMOSFET為RESURF LDMOSFET的一種改良版，藉由加大RESURF效果與提昇磊晶層濃度，可以使得其元件性能高於傳統的RESURF LDMOSFET。
本篇論文討論P-ring LDMOSFET的結構與製程參數，對於元件性能的影響，並且比較P-ring LDMOSFET與傳統RESURF LDMOSFET的差異。利用電腦模擬的方式，了解P-ring結構對於LDMOSFET崩潰電壓與導通電阻的影響。以及針對不同的製程參數，所得到的電腦模擬結果，使我們更能夠掌握P-ring LDMOSFET的元件性能變化，進而得以進行最佳化設計，充分發揮元件的效能。最終，我們認為未來P-ring LDMOSFET是一個不錯替代傳統RESURF LDMOSFET的選擇。另外，將P-ring的結構應用於其他的功率元件，也應具有研究價值與潛力。

In recently years, some elecrtonic systems become imporant and popular, especially for consumable and portable application. The representatives are MP3, cell phone and LCD monitor…etc. Among these products, power ICs play an important role. Basically, power ICs have two features which take high operating voltage and show low resistance.
RESURF LDMOSFET is one kind of power IC. It have the same I-V characteristic with MOSFET. It also can be produced by normal MOS process. So it is a suitable candidate for integrating with electronic devices. P-ring LDMOSFET is one advanced version. By enlarging RESURF effect and adjusting N-epi concentration, it would have more superior performance than traditional RESURF LDMOSFET.
This thesis will discuss the structure and some process parameters of P-ring LDMOSFET. And it will also compare the difference between traditional RESUF and P-ring LDMOSFET. According to computer simulation results, we could understand how to improve device performance. Finally, we think P-ring LDMOSFET have the potential to replace traditional RESURF LDMOSFET in the future.

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