以鈦鎢氮化物做矽離子佈植砷化鎵退火保護

Abstract

本論文係首先對反應離子鈦鎢氮化物做為經矽離子佈植砷化鎵基板退火保 護做廣汎而深入的研究.兩種在砷化鎵半導體工業中經常使用的退火保護, 電漿化學氣相沉積氮化夕及反應離子氮化夕被用來做比較.夕離子使用兩 種植入條件,高劑量及低劑量,退火溫度800度到950度,時間2秒到1200秒. 在最佳退火條件下,使用高劑量植入的砷化鎵試片若使用鈦鎢氮化物做退 火保護其載子濃度可達到使用電漿化學氣相沉積氮化夕當退火保護 95% 以及相同的載子遷移率.而在低劑量植入的條件下,使用鈦鎢氮化物做退火 保護的試片其活化率可達到使用離子濺鍍氮化矽做退火保護的90%,以及電 漿化學氣相氮化矽的103%.雷射激發光譜的結果顯示1.462EV與鎵空位有關 的缺陷出現在高溫退火後的鈦鎢氮(高氮含量)保護試片中,1.462EV 及1.396EV與砷空位有關的出現在低氮含量鈦鎢氮化物保護的試片中. RF SPUTTERED TIW NITRIDE AS AN ANNEALING ENCAPSULANT FOR SILICON IMPLANTED GaAs IS FIRSTLY EVALUATED IN THIS WORK. TWO KINDS OF COMMON ANNEALING ENCAPSULANTS, RF SPUTTERED SILICON NITRIDE AND PECVD SILICON NITRIDE, WERE DEPOSITED TO COMPARE THE DIFFERENCE. TWO KINDS OF IMPLANTATION CONDITION, HIGH DOSE 100KEV,DOSE 2E13 CM^-2 AND LOW DOSE 125KEV 5E12 CM^-2, WERE USED IN THIS EXPERIMENT. ANNEALING TEMPERATURE RANGES FROM 800 TO 950 DEGREE AND TIME RANGES FROM 2 TO 1200 SECOND BY USING RAPID THERMAL ANNEALING AND CONVENTIONAL FURNANCE ANNEALING. IN THE OPTIMAL ANNEALING CONDITION, THE CARRIER CONCENTRAION OF TIW NITRIDE CAPPED SAMPLES REACH 95% OF PECVDS' AND HAVE NEARLY THE SAME HALL MOBILITY FOR HIGH DOSE IMPLANTED SAMPLES. AVTIVATION EFFICIENCY OF TIW NITRIDE CAPPED SAMPLES REACH 90% OF SPUTTERED SILICON NITRIDES'AND 103% OF PECVD SILICON NITRIDES'. FROM THE SPECTRUM OF PHOTOLUMINESCENCE, 1.462EV GA VACANCY RELATED CENTER FOR TIW NITRIDE WITH HIGH NITROGEN CONTENT CAPPED SAMPLES AND 1.462 EV PLUS 1.396 EV AS VACANCY RELATED CENTER.