奈米等級PN接面二極體

Abstract

二極體元件，一直以來在積體電路中，具有相當廣泛的應用，其元件原理及特性，更是構成半導體元件的基石。現今半導體的特徵尺寸逐漸縮小至奈米等級，使得現有的理論觀念已不能用來解釋其效應特性。而利用其新的特性，勢必造成全新的應用層面發展。 目前以矽基材所做出來的太陽能電池，雖然被廣泛地使用，但其轉換效率卻不及以異質接面砷化鎵為基材的太陽能電池。其主要的原因在於矽元素屬於間接能隙的材料特性使然；然而，此一特性，使得矽具有較砷化鎵更多的光波長吸收範圍，但也相對地造成較大的飽和電流，致使漏電流增加，導致整體轉換效率下降。有鑑於此，本論文的研究方向，在於提出一個方法，用來改善矽基材的飽和電流特性。 本實驗透過電子束微影技術，來製作一矽奈米等級PN接面二極體元件，藉此特殊結構性質，來探討是否能夠有效地降低矽基材的飽和電流，並與傳統塊材PN二極體來相互比較，觀察兩種不同PN接面面積的二極體，其電性是否會有不同的表現方式。 關鍵字：二極體、電子束微影技術

“Diode” has so far been widely applied in the Very-large-scale integration (VLSI). What is more, the theorem and characteristics of its device also lay a solid foundation for the device of semiconductor. Nowadays, the feature size of semiconductor has been downsized into a nano-scale which makes the existing theories insufficient to explain both its effect and property. However, if well utilized, its novel property will lead into a brand-new application level. The Solar cell made of silicon substrate has currently been in an extensive application; nevertheless, its conversion efficiency is far disappointing when compared to solar cell made of heterojunction GaAs. The major explanation lays on the fact that the property of Si belongs to material of Non-direct energy band. This special property helps Si absorb more wavelength than GaAs; however, it also causes comparatively stronger Saturation Current in which the leakage effects are increased and the whole conversion efficiency is decreased accordingly. Hence, the research focus of this dissertation is aiming at proposing a method which hopefully will improve the property of saturation current of si-based. Through E-Beam Lithography, this experiment is intended to build a device of PN Junction diode made of Si material in a nano scale. Besides, the experiment also probes into whether the saturation current of Silicon substrate can be alleviated effectively out of its special structure and, what is more, in comparison with those traditional PN Junction diodes by observing two different PN Junction diodes to understand if their electrical characteristics will be different.