- 學位論文
800V多場環橫向雙擴散金氧半場效電晶體之設計
The Design of 800V Multiple Rings LDMOSFET
摘要
單降低表面電場(Single RESURF) LDMOSFET很難兼顧高崩潰電壓(Breakdown voltage)和低導通電阻(Ron，ON-state Resistance)對結構的要求。雙重降低表面電場 (Double RESURF) LDMOSFET為Single RESURF LDMOSFET的一種改良版，藉由加大RESURF效果與提昇漂移區濃度，可以使得其元件性能高於Single RESURF LDMOSFET。Double RESURF LDMOSFET技術雖然可以在提高漂移區摻雜濃度近兩倍時仍能保持較高的崩潰電壓，從而改善了崩潰電壓和導通電阻的折衷關係。雖然改善了導通電阻，但是仍然沒有辦法更進一步去提高崩潰電壓，因此，在改善崩潰電壓上依然需要改進。 本篇論文中設計多場環 (Multiple rings) LDMOSFET新結構，使漂移區更容易空乏，從而提高了崩潰電壓，並且也討論Multiple rings LDMOSFET的結構與製程參數，對於元件性能的影響，比較Multiple rings LDMOSFET與Single RESURF LDMOSFET和Double RESURF LDMOSFET的差異。借助Tsuprem-4和Medici，分析優化了元件的關鍵參數對崩潰電壓和導通電阻的影響，從而實現了元件的高崩潰電壓和低導通電阻的要求，可以很好地應用於各種高壓功率元件開發。 最終，優化顯示，該元件於漂移區長度小於70μm，就可實現800V以上的崩潰電壓，200mohm-cm2以下的導通電阻。未來我們認為Multiple rings LDMOSFET是一個不錯代替Single RESURF LDMOSFET和Double RESURF LDMOSFET的選擇。另外，將Multiple rings的結構應用於其他的功率元件，也應具有研究價值與潛力。
並列摘要
A single RESURF(Single REduce SURFace electronic field) LDMOSFET could not be possessed of a high off-state breakdown voltage while achieving a low on-state resistance. A Double RESURF(Double REduce SURFace electronic field) LDMOSFET is one advanced version. By enlarging RESURF effect and adjusting N-epi concentration, it would have more superior performance than traditional RESURF LDMOSFET. A Double RESURF LDMOSFET technology can improve doped of drift region at near twice the concentration to maintain a higher breakdown voltage, thus improving the breakdown voltage and on-resistance trade off. Although improved on-resistance, but still can not go further improve breakdown voltage, therefore, to improve the breakdown voltage is still the need to improve. This thesis will discuss the structure and some process parameters of Multiple rings LDMOSFET. And Multiple rings LDMOSFET and compared with the Single RESURF LDMOSFET and the Double RESURF LDMOSFET differences. According to Tsuprem-4 and Medici simulation results, we could understand how to improve device performance. Finally, we think Multiple rings LDMOSFET have the potential to replace traditional the RESURF LDMOSFET and the Double RESURF LDMOSFET in the future. In addition, the Multiple rings of the structure will be applied to other power components, it should have research value and potential.