本文關(guān)鍵詞： p型半導(dǎo)體氧化物 磁控濺射 Cu_xO薄膜 薄膜晶體管(TFT)　出處：《鄭州大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：21世紀(jì)以來,氧化物薄膜晶體管的研究和應(yīng)用取得了很大的進(jìn)展。其中n-TFT由于遷移率較高,在可見光區(qū)光透過率較高和可低溫制備等優(yōu)點(diǎn)已經(jīng)廣泛應(yīng)用于液晶顯示器件的制備,而p型氧化物材料較少且光電性能較差,嚴(yán)重阻礙了互補(bǔ)型金屬氧化物的研究進(jìn)展,因此非常有必要對(duì)p型半導(dǎo)體氧化物進(jìn)行研究。為了制備出性能較好的p型薄膜晶體管,本文著重對(duì)CuO-TFT的磁控濺射制備工藝和器件的性能進(jìn)行研究,文章的主要內(nèi)容包括以下幾個(gè)部分:本文采用射頻磁控濺射法,以金屬Cu為靶材,普通玻璃為襯底,在不同的氧分壓條件下鍍膜,經(jīng)過不同溫度的退火處理后分別進(jìn)行一系列的表征分析。XRD和XPS結(jié)果表明隨著氧分壓的增大,薄膜中的Cu逐漸被氧化,氧分壓為3%時(shí)薄膜為純相Cu_2O,3%以下的薄膜中含有Cu,3%以上則被氧化為CuO;隨著退火溫度的升高,薄膜中晶體的結(jié)晶質(zhì)量變好,晶粒尺寸增大;100 nm以下的Cu_xO薄膜在可見光波段的透過率均超過70%;不同工藝制備的薄膜的光學(xué)帶系寬度都在1.9 V~2.6 V之間;室溫下制得薄膜的載流子遷移率隨氧分壓的增大而增大,退火后載流子遷移率最大提升到8.433 cm2/Vs,載流子濃度最低可以降低到2.873×1013 cm-3。通過比較不同工藝條件下制備的薄膜的性能,確定兩種CuO薄膜的最佳制備工藝分別為:(1)本底真空度5×10~(-7) mbar,工作壓力3×10~(-3) mbar,射頻功率60 W,氧分壓3%,沉積時(shí)間1 min,600℃空氣中退火處理10 h。(2)本底真空度5×10~(-7) mbar,工作壓力3×10~(-3) mbar,射頻功率60 W,氧分壓7%,沉積時(shí)間3min,600℃空氣中退火處理10 h。用以上兩種工藝途徑制得的CuO作為有源層制備CuO-TFT器件,分析有源層制備工藝對(duì)TFT性能的影響。進(jìn)一步地,為了分析不同工藝條件對(duì)TFT性能的影響,本文采用錯(cuò)排型底柵極(S-BG)結(jié)構(gòu)制備出“Si-SiO_2-CuO-Al”薄膜晶體管器件,其中CuO薄膜分別采用上述兩種工藝制得。兩個(gè)CuO-TFT器件都是典型的p型溝道增強(qiáng)型TFT器件,都具有良好的柵壓調(diào)控性能,器件都有較為明顯的飽和性。其中用上文(1)條件制備的CuO作為有源層的TFT器件電學(xué)性能較好,其場(chǎng)效應(yīng)遷移率為0.32 cm2/Vs、開關(guān)電流比為3.0×102、閾值電壓為-9 V、亞閾值擺幅約為5.4 V/dec、界面態(tài)密度為1.4×1012 cm-2�？傮w來看,兩個(gè)TFT器件的電學(xué)性能并不理想,這可能是因?yàn)樵赥FT器件有源層和絕緣層界面處存在較高密度的空穴陷阱態(tài)。最后,對(duì)CuO-TFT轉(zhuǎn)移特性曲線進(jìn)行了正反向掃描測(cè)試和受環(huán)境影響的測(cè)試,CuO-TFT經(jīng)過正反向掃描后其轉(zhuǎn)移特性曲線產(chǎn)生了1 V左右的滯回電壓。在大氣中放置一段時(shí)間后,TFT轉(zhuǎn)移特性曲線整體向上漂移,關(guān)態(tài)電流明顯增大,同時(shí)閾值電壓發(fā)生負(fù)向偏移。而且放置時(shí)間越長(zhǎng),漏電流增大越明顯。
[Abstract]:Since 21th century, great progress has been made in the research and application of oxide thin film transistors, in which n-TFT has been widely used in the fabrication of liquid crystal display devices due to its high mobility, high optical transmittance and low temperature fabrication in the visible region. However, there are few p-type oxide materials and poor optoelectronic properties, which seriously hinder the research progress of complementary metal oxides, so it is necessary to study p-type semiconductor oxides. In order to prepare p-type thin film transistors with better performance, In this paper, the preparation technology of CuO-TFT magnetron sputtering and the properties of the devices are studied. The main contents of this paper are as follows: in this paper, the RF magnetron sputtering method is used, the metal Cu is used as the target material, the common glass is used as the substrate, After annealing at different temperatures under different oxygen partial pressure conditions, a series of characterization analysis and XPS results showed that Cu in the film was oxidized gradually with the increase of oxygen partial pressure. When the oxygen partial pressure is 3, the films with pure phase Cu _ 2O _ 3% or less are oxidized to CuO by more than 3% Cu _ 2O _ 3. With the increase of annealing temperature, the crystal quality of the films becomes better. The transmittance of Cu_xO films below 100nm is higher than 70nm, the width of optical band system is between 1.9V and 2.6V. the carrier mobility of the films increases with the increase of oxygen partial pressure at room temperature, and the optical band width of the films is between 1.9V and 2.6V. at room temperature, the carrier mobility of the films increases with the increase of the oxygen partial pressure, and the optical band width of the films is between 1.9V and 2.6V. After annealing, the maximum carrier mobility is increased to 8.433 cm ~ 2 / V _ s, and the lowest carrier concentration can be reduced to 2.873 脳 10 ~ (13) cm ~ (-3). The optimum preparation conditions of the two CuO films were determined as follows: 1) background vacuum 5 脳 10 ~ (-1) m ~ (-1), working pressure 3 脳 10 ~ (-1) m ~ (-1), RF power 60 W, oxygen partial pressure 3 W, deposition time 1 min ~ 600 鈩，

本文編號(hào)：1523341