本文選題：β-Ga2O3 + 分子束外延�。� 參考：《電子科技大學(xué)》2015年碩士論文

【摘要】：近年來,日盲紫外探測技術(shù)因其抗干擾能力強、靈敏度高的優(yōu)點被廣泛關(guān)注。而基于寬禁帶半導(dǎo)體的日盲紫外探測器則因其體積小、壽命長、功耗低等優(yōu)點,逐步取代真空光電管成為了當(dāng)前的主流研究方向。相較于Al Ga N、Zn Mg O等常見的日盲紫外敏感材料,β-Ga2O3更容易制備出高質(zhì)量的薄膜,而且具備較大的禁帶寬度,非常適合用于制造日盲紫外探測器。本文利用分子束外延工藝在c面藍(lán)寶石基片上生長β-Ga2O3薄膜,進而研制基于該薄膜的光電導(dǎo)日盲紫外探測器。首先,從材料特性的角度出發(fā),研究了氧化鎵薄膜的制備處理方法與日盲紫外探測器主要性能指標(biāo)的聯(lián)系。在此基礎(chǔ)之上,為實現(xiàn)器件小型化,為后期大面陣的研制打下基礎(chǔ),本論文又從器件結(jié)構(gòu)的角度,研究了器件的縮放特性,并探索了二極管輔助光電導(dǎo)探測器結(jié)構(gòu)。具體研究內(nèi)容主要分為以下幾個部分:(1)論文研究了退火對β-Ga2O3薄膜質(zhì)量及其制備的光電導(dǎo)日盲紫外探測器性能的影響。本文在800 oC、900 oC、1000 oC、1100 oC四個溫度和真空(4.8×10-4Pa)、氧氣、氮氣三種氣氛下對分子束外延生長的β-Ga2O3薄膜進行了退火處理,并利用X射線衍射以及光敏特性測試分別對樣品的材料和器件性能進行對比分析,以深入了解退火工藝對β-Ga2O3薄膜質(zhì)量和光敏特性的影響規(guī)律。研究結(jié)果顯示:隨著退火溫度的升高,薄膜的(4__02)衍射峰相對強度逐漸降低,探測器的光電流與暗電流均逐漸下降,器件光響應(yīng)逐漸衰退。氧氣退火和氮氣退火會影響薄膜中的載流子濃度,從而改變器件的光電流和暗電流。此外,氧氣退火還可以減少探測器的下降時間,有效降低持續(xù)光電導(dǎo)效應(yīng)。(2)論文研究了藍(lán)寶石基片原位退火對β-Ga2O3薄膜質(zhì)量以及光電導(dǎo)日盲紫外探測器性能的影響。為了改善薄膜與基片之間的晶格失配問題,本論文嘗試在藍(lán)寶石基片與β-Ga2O3薄膜中引入同質(zhì)緩沖層,由于緩沖層制備工藝尚不成熟,未能有效改善β-Ga2O3薄膜的質(zhì)量。但是,研究中發(fā)現(xiàn):在生長β-Ga2O3薄膜之前,先在760oC溫度下對藍(lán)寶石基片進行半小時的原位退火處理,可以將薄膜的FWHM從2.0左右降低到1.0左右,有效提高了晶粒取向的一致性,說明基片原位退火處理可明顯改善薄膜的生長質(zhì)量。通過器件制備實驗,本論文還發(fā)現(xiàn),氧化鎵薄膜的質(zhì)量越好,光電導(dǎo)探測器的光電流越大,響應(yīng)度越高,但器件的暗電流也越大,光暗電流比反而會減小,此外,氧化鎵薄膜質(zhì)量對光電導(dǎo)探測器的時間響應(yīng)特性也有明顯影響,薄膜質(zhì)量越好,光電導(dǎo)探測器的上升時間越短而下降時間越長。(3)論文探討了了β-Ga2O3薄膜光電導(dǎo)日盲紫外探測器的縮放特性。在保持薄膜生長工藝參數(shù)不變的前提下,對光電導(dǎo)日盲紫外探測器的尺寸進行等比例的放大或縮小,通過對各個不同尺寸大小的器件進行性能測試,研究了光電導(dǎo)日盲紫外探測器的器件尺寸對其光電流、暗電流、響應(yīng)度以及時間響應(yīng)特性等性能參數(shù)的影響。研究結(jié)果顯示:隨著器件尺寸的等比縮小,器件的光電流會有輕微的上升趨勢,但整體變化不大。隨著尺寸的縮小,器件的響應(yīng)度會有明顯增加,時間響應(yīng)特性基本不發(fā)生變化。因此,叉指電極結(jié)構(gòu)的光電導(dǎo)探測器在經(jīng)過等比縮小后可以用于大面陣的制作。但叉指電極結(jié)構(gòu)的問題在于,隨著器件尺寸的縮小,指條寬度以及指間距會變得非常窄,給器件的加工制造帶來了難度。(4)論文探索了二極管輔助光電導(dǎo)日盲紫外探測器。相較于基于叉指電極的器件結(jié)構(gòu),該新型器件結(jié)構(gòu)在制作工藝上難度更小,而且,通過外接齊納二極管可以明顯增大日盲紫外探測器的光信號與暗信號之間的差值,增強器件的性能,該器件結(jié)構(gòu)的可行性在本工作中已得到初步驗證,有希望用于大面陣的研制。
[Abstract]:In recent years, the daily blind ultraviolet detection technology has been widely concerned because of its strong anti-interference ability and high sensitivity. And the daily blind ultraviolet detector based on wide band gap semiconductor has been gradually replacing vacuum phototube because of its small size, long life and low power consumption. It is more common than Al Ga N, Zn Mg O and other common days. The blind UV sensitive material, the beta -Ga2O3 is more easily prepared with high quality thin film, and has a large band gap. It is very suitable for the manufacture of the blind ultraviolet detector. In this paper, we use the molecular beam epitaxy technology to grow the beta -Ga2O3 film on the sapphire base on the C surface, and then develop the optoelectronic blind ultraviolet detector based on this film. On the basis of the study of the relationship between the preparation of gallium oxide film and the main performance index of the daily blind ultraviolet detector, this paper has studied the scaling characteristics of the device and explored the diode on the basis of miniaturization of the device and the foundation for the development of the later large surface array. The main content of the auxiliary photoconductive detector is divided into the following parts: (1) the effects of Annealing on the quality of the beta -Ga2O3 film and the performance of the optoelectronic blind UV detector are studied. This paper is in the three atmosphere of three atmospheres in the atmosphere of four temperatures and four temperatures and vacuum (4.8 * 10-4Pa), 4.8 * 10-4Pa, and 1100 oC. The beta -Ga2O3 thin films grown by beam epitaxy were annealed, and the properties of the materials and devices were analyzed by X ray diffraction and photosensitivity test. The effect of annealing process on the quality and photosensitivity of beta -Ga2O3 films was deeply understood. The results showed that the film was (4__) with the increase of annealing temperature. 02) the relative intensity of the diffraction peak decreases gradually, the photocurrent and the dark current of the detector gradually decrease, and the optical response of the device declines gradually. The oxygen annealing and nitrogen annealing will affect the carrier concentration in the film, thus changing the photocurrent and dark current of the device. In addition, the oxygen annealing can also reduce the drop time of the detector and effectively reduce the duration of the detector. Photoconductivity effect. (2) the effect of the in-situ annealing of sapphire substrate on the quality of beta -Ga2O3 film and the performance of optoelectronic blind UV detector is studied. In order to improve the lattice mismatch between the film and the substrate, this paper attempts to introduce the homogenous buffer layer in the sapphire substrate and the beta -Ga2O3 film, because the preparation process of the buffer layer is not yet available. It is not effective to improve the quality of the beta -Ga2O3 film. However, it is found that before the growth of the beta -Ga2O3 film, a half hour annealing treatment of the sapphire substrate at 760oC temperature can reduce the FWHM from about 2 to about 1, which effectively improves the consistency of grain orientation, indicating the in-situ annealing place of the substrate. It is also found that the better the quality of the gallium oxide film is, the greater the photocurrent of the photoconductive detector is, the higher the response degree is, the larger the dark current and the decrease of the light dark current ratio, in addition, the time response of the gallium oxide film to the photoconductive detector is special. The better the quality of the film, the better the quality of the film, the shorter the rise time of the photoconductive detector and the longer the drop time. (3) the paper discussed the zoom characteristic of the blind UV detector of the photoconductivity of the beta -Ga2O3 film. The effect of the device size on the photocurrent, the dark current, the response degree and the time response characteristic of the optoelectronic blind UV detector is studied by measuring the performance of the devices with different sizes. The results show that the photocurrent of the device will be slight with the size of the device size reduced. As the size decreases, the response degree of the device will increase obviously, and the response characteristic of the time is basically not changed. Therefore, the photoconductive detector of the cross finger electrode structure can be used for the fabrication of large array after the reduction of the equal ratio. But the problem of the structure of the interdigital electrode is that the size of the device is reduced. The width of the finger and the distance between the fingers will become very narrow, and the processing and manufacturing of the devices are difficult. (4) the paper explored the diode assisted optoelectronic blind UV detector. Compared with the device based on the cross finger electrode, the new device structure is less difficult in the fabrication process and can be significantly increased by the external zener diode. The difference between the light signal and the dark signal of the sun blind ultraviolet detector enhances the performance of the device. The feasibility of the device structure has been preliminarily verified in this work, and it is expected to be used for the development of large array.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TN23
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本文編號：2012234