本篇論文是對0.35 微米製程的P 通道橫向擴散金氧半場效電晶體元件(LDMOS)探討因熱載子所造成元件特性退化的現象與機制。並發現元件特性退化會受到量測元件電性參數電壓的嚴重影響，此外，熱載子效應也會導致安全操作面積(SOA)大幅下降的現象。對電路設計而言，此兩現象必須考慮進去。
經由熱載子實驗量測求得元件可靠度分析結果，發現熱載子造成元件的臨限電壓(VT)嚴重的降低。為了找出其原因，利用了 TCAD 模擬軟體(Technology computer-aided design simulation) 和 ChargePumping 量測技術，結果顯示，在通道區域中由於熱電洞注入所造成的表面狀態(Nit)與捕陷電荷(Not)是造成顯著臨限電壓偏移的因素。
因實際電路應用上，元件不一定皆工作在操作電壓，亦及可能工作在低於操作電壓的情況。因此在本篇論文中也去改變元件電性參數(Idlin、Idsat、Ron)的量測電壓來探討其因熱載子造成元件退化結果是否一致，實驗結果發現元件在低閘極電壓(Vg)量測電性參數條件下，其退化更為嚴重，元件使用壽命(lifetime)更低。此結果使得傳統評估元件使用壽命的方式不再適用，在本論文中提出了一個正確評估元件使用壽命的方法。
對電路設計而言，元件的安全操作面積(SOA)是一個相當重要的指標。因此在本論文的最後也去探討熱載子效應對SOA 影響。實驗發現，熱載子效應會導致SOA 大幅下降的現象。為了解釋其原因，使用了 TCAD 模擬、量測Ibs/Ids (substrate current/drain current)的方法以及最大橫向電場模型。

In this thesis, the experiment studies on the phenomena and mechanisms of hot-carrier-induced degradation in 0.35 μm p-type lateral double diffusion metal oxide semiconductor field-effect-transistors. The experiments found that measure voltage of device electrical parameters deeply affects the amount of hot-carrier-induced degradation. Besides, the hot carrier effects also causes the safe operating area (SOA) to decrease largely. This phenomenon must be considered for circuit designs.
After hot carrier stress experiment on the device, the threshold voltage (VT) decreases seriously. To find reason, TCAD simulation and Charging Pumping method are used. Experimental results indicate that donor-type interface traps created by hole injection in the channel region is the dominant factor for significant VT shift.
The devices not always work on operational voltage for actual circuits applications. In order words, the devices maybe work on the IV lower voltage compared with operational voltage. For this reason, the hot-carrier-induced degradation extracting at different voltage are investigated. Experimental results indicate that degradation extracting at low gate voltage is more serious. This phenomenon causes the traditional device lifetime is not correct. In this thesis, a correct method estimating device lifetime is presented.
The safe operating area (SOA) is an important index for circuit designs, hence the effect of hot carrier stress on SOA is investigated at last in the thesis. We find that hot carrier cause SOA to decrease largely. In order to explain this phenomenon, TCAD simulation, the method which measuring substrate and drain current and the model for the maximum lateral electric field (Eymax) are used.

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