陳敏璋臺灣大學：材料科學與工程學研究所廖宏昌Liao, Hung-ChangHung-ChangLiao2007-11-262018-06-282007-11-262018-06-282007http://ntur.lib.ntu.edu.tw//handle/246246/55333氧化鋅(Zinc Oxide, ZnO)為Ⅱ-Ⅵ族化合物半導體，具有直接能隙(Direct Bandgap)的能帶結構，能隙的大小為3.37eV，所對應的發光範圍在紫外光區段，並具有高達60meV的Exciton Binding Energy。此外，由於ZnO具有透光率高以及電阻率低的特性，亦可作為透明導電層的應用。因此ZnO被認為是未來非常重要的光電材料。本論文利用原子層沉積(Atomic Layer Deposition, ALD)技術在矽基板上成長高品質的ZnO薄膜。首先我們使用兩階段成長以及退火的方式在晶面為(111)的矽基板上成長具有(002)擇優取向的高品質ZnO薄膜，結果顯示緩衝層的晶體品質決定了整個ZnO晶體結構的優劣。此外，藉由ALD技術可以精準控制薄膜厚度與成分的特性，我們亦製作奈米混層結構，在ZnO中摻雜Al以增加電子濃度並降低電阻率，並製作出符合抗反射層所需折射率的薄膜。我們成功的在Al摻雜濃度為2%時得到最低電阻率為1.78×10-3 Ω-cm與折射率為1.96的ZnO:Al薄膜，並在波長範圍545nm至555nm間得到小於0.2%的反射率。最後我們將ZnO:Al薄膜成長在具有Al2O3表面鈍化層的矽基板上製作n-ZnO/Al2O3/p-Si穿隧二極體。當元件在逆向偏壓操作時，由於ZnO:Al薄膜具有良好的抗反射效果，元件吸收波長為532nm的入射光之光電轉換量子效率可達97.8%。另一方面，當元件操作在順向偏壓時，由於ZnO:Al薄膜內的缺陷提供了p-Si內的電洞利用穿隧效應進入ZnO:Al薄膜的途徑，這些電洞進而與ZnO:Al導電帶的電子結合而發光，因此我們量測到波長在590nm的可見光發光頻譜。inc oxide is a II-VI semiconductor material with direct band-gap of 3.37eV corresponding to the light emission in the ultraviolet region. ZnO also has large excton binding energy (~60meV). In addition, ZnO can be used as transparent conducting oxide since it has low resistivity and high transparency in the visible region. As a result, ZnO is considered as a promising material for the application to the optoelectronics. In this thesis, we studied the growth of high-quality ZnO thin films on the silicon substrates by atomic layer deposition (ALD). We used two-step approach with high-temperature post-deposition annealing to grow ZnO with high (0002) orientation on the Si (111) substrate. It was shown that the crystal quality of the buffer layer significantly influenced the quality of the ZnO films. We also deposited the Al-doped ZnO (ZnO:Al) thin films to act as the transparent conducting oxide as well as the anti-reflection coating layer on the silicon substrates. The ZnO:Al thin film with the refractive index of 1.96 and the resistivity as low as 1.78×10-3 Ω-cm was achieved. The reflectivity of the ZnO:Al film on the silicon substrate was below 0.2% in the wavelength region between 545nm to 555nm. Finally, we deposited the n-type ZnO:Al thin film on the p-type silicon substrate with a thin Al2O3 surface-passivating layer to form an n-ZnO/Al2O3/p-Si tunneling diode. When the device was operated at reverse bias to act as a photodetector, the external quantum efficiency was up to 97.8% with the incident light at the wavelength of 532nm due to the anti-reflection coating effect of the ZnO:Al film. When the device was at forward bias, the holes in the p-type silicon tunneled into the defect states in ZnO:Al and then radiatively recombined with the electrons in ZnO:Al film, thus yielding an electroluminescence spectra at the wavelength at 590nm.口試委員審定書.............................................i 致謝......................................................ii 中文摘要.................................................iii 英文摘要..................................................iv 第一章　序論...............................................1 1-1　研究動機..............................................1 1-2　文獻回顧..............................................2 1-3　原子層沉積技術........................................6 1-3-1　原子層沉積技術之原理與特性..........................6 1-3-2　原子層沉積技術之製程因素............................8 1-3-3　原子層沉積技術設備之簡介...........................11 1-4　論文導覽.............................................13 1-5　參考文獻.............................................14 第二章　成長高品質氧化鋅於矽基板之研究....................15 2-1　簡介.................................................15 2-2　實驗方法.............................................16 2-3　緩衝層之成長.........................................18 2-3-1　緩衝層的退火溫度...................................18 2-3-2　緩衝層的退火時間...................................22 2-4　在緩衝層上成長主要層.................................23 2-4-1　緩衝層熱處理對主要層的影響.........................23 2-4-2　主要層退火處理與晶體品質的關係.....................27 2-4-3　主要層成長溫度對晶體品質之影響.....................29 2-4-4　主要層退火時間的影響...............................31 2-5　結果與討論...........................................32 2-6　參考文獻.............................................33 第三章　氧化鋅薄膜作為矽晶太陽能電池抗反射層以及透明電極之研究..34 3-1　簡介.................................................34 3-2 實驗方法.............................................35 3-3　氧化鋅成長速率.......................................39 3-4　摻雜濃度與電阻率及折射率的關係........................................................41 3-5　溫度變化對電阻率與折射率的影響.......................43 3-6　反射率的量測.........................................48 3-7　結果與討論...........................................48 3-8　參考文獻.............................................50 第四章　氧化鋅成長於矽基板上製作光偵測器與發光二極體之研究51 4-1　前言.................................................51 4-2 薄膜沉積與元件製作...................................51 4-2-1　氧化物之沉積.......................................51 4-2-2　元件製程...........................................54 4-3　實驗結果與討論.......................................56 4-3-1　光偵測器之量測與討論...............................56 4-3-2　發光二極體之量測與討論 ............................62 4-4　結論.................................................64 4-5　參考文獻.............................................64 第五章　總結..............................................651628483 bytesapplication/pdfen-US原子層沉積技術氧化鋅透明導電層抗反射層光偵測器發光二極體atomic layer depositionZnOtransparent conducting oxideanti-reflection coatingphotodetectorlight-emitting diodethesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/55333/1/ntu-96-R94527065-1.pdf