與互補式金氧半製程相容的高增益閘型側向雙載子電晶體﹕特性分析､模型､及應用

Abstract

本論文係提出與現今互補式金氧半製程相容的高增益閘型側向雙載子電晶 體的特性分析、模型、及其應用。詳盡的閘型側向雙載子電晶體的電流— 電壓特性被量測出來，亦且被探究之。其集極電流基本上包括兩個部份： 一個部份是閘極可控的，另一部份是非閘極可控的。利用實驗量測的方式 ，這兩個部份電流被區分了開來。針對每一部份電流，我們成功地建立起 與實驗數據相當吻合的解析式模型。低注入下的集極電流係由擴散電流所 主宰，同時閘控部份電流呈現與通道表面電位為指數正比的特性。對於p- n-p 閘型側向雙載子電晶體而言，閘控部份電流則與基體最低電位呈指數 正比的特性而非通道表面電位。我們發現了基極電流反向現象。經由實驗 及二維元件模擬證明，此現象可歸究於累增載子產生的結果。從同一製程 下的實驗資料分析，我們發現倍增比值隨著集極電壓呈指數上升並與順向 射極偏壓(Veb) 和通道寬長比(W/L) 無關。關於閘型側向雙載子電晶體的 累增載子產生的模型被提出來。我們可以發現在低注入下的累增載子產生 電流與參數(Vcb+Φbi-ψso) 有強烈的關係。此外，在集極臨界電壓 (Vcr) 和起始電流增益(β)的相互關係可利用這個模型推導出來。我們亦 發現窄基極寬度的閘型側向雙載子電晶體集極電流將受到集極偏壓的嚴重 影響，這是由於基極寬度的調變和集極引發能障降低效應所引起。針對此 效應，我們亦建立起與實驗數據相當吻合的解析式模型。最後，我們提出 兩種閘型側向雙載子電晶體的特殊的應用—一是閘型藍達雙載子電晶體， 而另一是新式靜態隨機存取記憶體單元結構的實驗性質的雛型。 This dissertation presents the characterization, the model- ing, and the applications of the high-gain gated lateral bipo- lar transistors which are compatible with the present CMOS technology. The I-V characteristics of the gated lateral BJTs have been extensively measured and investigated. The collector terminal current essentially contains two distinct components: one is gate controllable and the other is independent of gate bias. These two components have been experimentally separated and analytically modeled for both npn and pnp devices. Base current reversal phenomenon is newly observed. We attribute this phenomenon to avalanche generation as verified experimentally and by 2-D device simulation. The model of the avalanche generation in the gated lateral bipolar transistor has also been given. Also, the relationship between the collector critical voltage (Vcr) and the initial curent gain (β) has been newly derived by utilizing our proposed model. Also established for the narrow base case is the analytical expressions yielding good agreement with the experimental data. Finally, we have proposed two special kinds of applications utilizing the gated lateral BJTs.