磷化銦蕭基二極體之製備與特性量測

Abstract

在本論文裡,主要是對蕭基二極體的電性作探討,並以MIS結構及MS結 構之低溫製程來作改良,其中MIS結構中的絕緣層是以PECVD方式沉積的 PxNy,而電性的分析主要是經由電流電壓及電容電壓的量測來加以探討.對 MIS結構的蕭基元件[Au/PxNy(40A)/n-InP]而言,其反向飽合電流密度 為3.3*e-7 A/cm2,蕭基位障為0.74eV,理想因子為1.24.對於MS結構的蕭基 元件[Au/n-InP]我們是以低溫條件來作蒸鍍,且其反向飽合電流密度 為1.6*e-7 A/cm2.蕭基位障為0.76eV,理想因子為1.2.以上兩種不同製程 所得之蕭基位障均比室溫蒸鍍的MS結構蕭基元件[Au/n-InP]的0.5eV高 出0.24~0.26eV.另外我們亦對此等結構之蕭基接面作退火處理,結果顯示 退火的樣品其蕭基位障降低,理想因子會有靠近理想值1的趨勢. In this thesis, we investigated the electrical characterization of InP Schottkydiodes. The methods applied to improve the characterization of Schottky diodeswere to use MIS diodes structure with PxNy deposited on InP substrates and conventional MS diode structure but processed at low temperature 77K. I-V andC-V measurements were performed to characterize the devices. For MIS Schottkydiode [Au/PxNy(40A)/n-InP], the saturation current density is 3.3*e-7 A/cm2,the barrier height is 0.74eV, and the ideality factor is 1.24. For MS Schottkydiode [Au/n-InP] fabricated at low temperature, the saturation current densityis 1.6*e-7 A/cm2, the barrier height is 0.76eV, and the ideality factor is 1.2.The barrier height of Schottky diodes fabricated by these two processes are 0.24~0.26eV higher than that of MS [Au/n-InP] Schottky diodes fabricated at room temperature. In addition, we heated the samples to 250C~300C for 4 minutesto study the temperature effect on the Schottky diodes. Lower barrier, smallerideality factor, and internal resistance were found and were attributed to theeffect of the annealing process on these such prepared Schottky diodes.