本文選題：β-Ga_2O_3薄膜 + 磁控濺射��； 參考：《浙江理工大學(xué)》2017年碩士論文

【摘要】：氧化鎵(Ga_2O_3)是一種新型的寬禁帶半導(dǎo)體材料,禁帶寬度約為4.98 eV,有五種同分異構(gòu)體(α、β、γ、ε、δ),其中最穩(wěn)定的是β-Ga_2O_3。β-Ga_2O_3有許多良好的物理性能,如:禁帶寬度大,擊穿場強高,介電常數(shù)大,在可見光和紫外光波段透過率高,熱穩(wěn)定性和化學(xué)穩(wěn)定性好,在未來的電子器件中具有重要的應(yīng)用前景,如:日盲紫外光電探測器、場效應(yīng)晶體管、透明導(dǎo)電電極等。與一般氧化物半導(dǎo)體類似,本征β-Ga_2O_3通常表現(xiàn)出n型導(dǎo)電,并由于氧空位等缺陷的自補償效應(yīng),p型Ga_2O_3很難獲得。但器件的應(yīng)用又往往基于pn結(jié)。理論上,二價元素的摻雜將會實現(xiàn)Ga_2O_3薄膜的p型轉(zhuǎn)變。本論文利用磁控濺射方法分別制備了Zn和Mg二價元素?fù)诫s的Ga_2O_3薄膜,并采用X射線衍射,紫外-可見分光光度計,X射線光電子能譜分析儀等手段對摻雜前后薄膜的結(jié)構(gòu)特性、表面形貌、光學(xué)性能、元素成分進(jìn)行了分析。同時,我們還制備了基于本征Ga_2O_3薄膜和摻雜Ga_2O_3薄膜的金屬-半導(dǎo)體-金屬(MSM)結(jié)構(gòu)的日盲紫外光電探測器元件,研究摻雜對Ga_2O_3薄膜日盲紫外探測器元件性能的影響。本文的主要研究內(nèi)容與結(jié)論如下:(1)本文采用磁控濺射法研究了β-Ga_2O_3薄膜的生長條件,主要研究了襯底溫度和沉積壓強對薄膜質(zhì)量和結(jié)晶性能的影響,獲得了β-Ga_2O_3薄膜的最佳生長條件為襯底溫度750℃,沉積氣壓0.8 Pa。(2)采用磁控濺射法制備了Zn摻雜Ga_2O_3薄膜,通過在Ga_2O_3靶材上放置不同顆粒的ZnO小片獲得不同Zn摻雜濃度的Ga_2O_3薄膜,對摻雜薄膜的結(jié)構(gòu)特性,元素成分,光學(xué)性能和電學(xué)性能進(jìn)行了表征。摻雜后得到的薄膜仍是單斜晶系的β-Ga_2O_3薄膜,由于Zn2+半徑大于Ga3+,摻雜后薄膜的XRD衍射峰向小角度偏移。隨著Zn摻雜濃度的增加,薄膜的禁帶寬度變小,這是由于摻雜引入了雜質(zhì)能級。摻雜薄膜日盲紫外光電探測器元件在365 nm紫外光激發(fā)下沒有響應(yīng),在254 nm紫外光激發(fā)下最大的光暗比達(dá)到110,而本征Ga_2O_3薄膜在254 nm紫外光激發(fā)下的光暗比最高為30,而且由于Zn的摻雜減少了薄膜中氧空位濃度,相比于本征Ga_2O_3薄膜,摻雜后的薄膜具有更快的響應(yīng)時間。采用磁控濺射法制備了Mg摻雜Ga_2O_3薄膜,研究了Mg摻雜對Ga_2O_3薄膜結(jié)構(gòu),性能的影響。由于Mg2+的半徑大于Ga3+,所以摻雜后薄膜衍射峰向小角度偏移。制備了基于Mg摻雜Ga_2O_3薄膜的金屬-半導(dǎo)體-金屬(MSM)結(jié)構(gòu)的日盲紫外光電探測器元件,相比于本征氧化鎵薄膜,具有更快的響應(yīng)時間。并且在不同偏壓下該器件具有良好的可重復(fù)性和高的穩(wěn)定性。(3)我們對Zn和Mg摻雜薄膜進(jìn)行了不同溫度的退火處理,隨著退火溫度的增加,供給原子吸收的能量越來越高,使得晶粒在擇優(yōu)取向時有足夠的能量進(jìn)行重排,所以摻雜薄膜的結(jié)晶性越來越好。當(dāng)退火溫度為900℃時,Mg摻雜氧化鎵薄膜晶粒的擇優(yōu)生長發(fā)生變化。且隨著退火溫度的升高,摻雜薄膜的光學(xué)帶隙變大。
[Abstract]:Ga2O3 is a new type of wide band gap semiconductor material, with a band gap of about 4.98 EV and five isomers (偽, 尾, 緯, 蔚, 未), of which the most stable is the 尾 -Ga2O3.The 尾 -Ga2O2O3 has many good physical properties, such as: wide bandgap, high breakdown field strength, large dielectric constant, It has high transmittance, thermal stability and chemical stability in visible and ultraviolet bands, and has important application prospects in the future electronic devices, such as solar blind ultraviolet photodetectors, field effect transistors, transparent conductive electrodes, etc. Similar to general oxide semiconductors, intrinsic 尾 -Ga2O3 usually exhibits n-type conduction, and it is difficult to obtain p-type Ga_2O_3 due to self-compensation effect of defects such as oxygen vacancies. However, the applications of devices are often based on PN junctions. Theoretically, the doping of bivalent elements will realize the p-type transition of Ga_2O_3 thin films. In this paper, Zn and mg doped Ga_2O_3 thin films were prepared by magnetron sputtering, and the structure characteristics of the films before and after doping were investigated by means of X-ray diffraction, UV-Vis spectrophotometer and X-ray photoelectron spectroscopy (XPS). Surface morphology, optical properties and elemental composition were analyzed. At the same time, we have fabricated solar blind UV photodetectors based on intrinsic Ga_2O_3 thin films and metal-semiconductor-metal Ga_2O_3 doped Ga_2O_3 thin films. The effect of doping on the performance of Ga_2O_3 thin film solar blind UV detectors is studied. The main contents and conclusions of this paper are as follows: (1) in this paper, the growth conditions of 尾 -Ga2O3 thin films are studied by magnetron sputtering, and the effects of substrate temperature and deposition pressure on the quality and crystallization properties of the films are studied. The optimum growth conditions of 尾 -Ga2O3 thin films were obtained as follows: substrate temperature 750 鈩，

本文編號：1898610