溶液蝕刻的矽奈米線之傳輸特性探討

利用溶液蝕刻法得到矽奈米線有大面積製造和低成本等優點。我們對不同型態的單晶矽晶圓進行蝕刻，進而得到矽奈米線陣列，在SEM和TEM分析下確認得到的奈米結構為單晶的矽奈米線，也藉由調控蝕刻時間來控制矽奈米線長度，發現奈米線長度20 um以上的矽奈米線陣列擁有99%以上的光吸收率，非常適合應用於光偵測與太陽能電池領域。我們使用微影製程，分別將p-type和n-type矽奈米線製作成單根奈米場效電晶體元件，以背向閘極的方式對FET施加閘極電壓，分析探討矽奈米線的半導體特性，並計算其載子濃度和載子遷移率等傳輸特性。因為矽奈米線都是從單晶的矽晶圓蝕刻後得到，在理想狀態下，同一片矽晶圓得到的矽奈米線應該有一樣的載子濃度，經過計算與統計後，大部分同型態元件的載子濃度和元件特性相當均勻。p-type和n-type矽奈米線平均載子濃度分別為1.15x1018 cm-3與2.61x1017 cm-3，而載子遷移率平均值分別為6.66x10-3 cm2/Vs和5.41x10-3 cm2/Vs。

關鍵字

場效電晶體；矽奈米線；溶液蝕刻；傳輸特性

並列摘要

Si nanowires (NWs) were obtained by using wet chemical etching method, this method can be served as the low-cost and mass production technique. The Si wafer with different types were used to acquire the Si NWs with the identical material properties. The lengths of p-Si NWs can be controlled to be 22.5 um, 31.5 um, 45.5 um and 48.7 um with the etching time of 100 min, 200 min, 300 min and 400 min, respectively. The absorbances of etched Si NW arrays are more than 99% , indicating that Si NW arrays have good light trapping ability. Wet-chemical-etched Si NW arrays exhibit very low reflection and strong absorption so they have potential for photodetectors and solar cells. Further, the fabrication of p-type and n-type Si NW field effect transistors (FETs) were achieved using lithography. The carrier concentrations and mobility of devices can be extracted from I-V characteristics. The carrier concentrations of p-Si NW and n-Si NW were determined to be 1.15x1018 cm-3 and 2.61x1017 cm-3, respectively. Moreover, the average carrier mobility of p-Si NW and n-Si NW are 6.66x10-3 cm2/Vs and 5.41x10-3 cm2/Vs, respectively.

並列關鍵字

FETs ； Si NW ； wet chemical etching ； electrical properties

參考文獻

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溶液蝕刻的矽奈米線之傳輸特性探討

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