發(fā)布時間：2018-06-27 14:22

  本文選題：氮化鋁 + 氮化鎵�。� 參考：《西安電子科技大學(xué)》2016年博士論文

【摘要】：與傳統(tǒng)的肖特基柵HEMT相比,GaN基絕緣柵HEMT器件可以有效減小柵極泄漏電流,在高效微波功率放大器、高壓開關(guān)等應(yīng)用中具有廣闊的應(yīng)用前景。然而,柵絕緣層與氮化物之間嚴(yán)重的界面問題會引起器件性能退化和可靠性問題,近年來成為國際研究的熱點。本論文創(chuàng)新性地采用AlN柵絕緣層替代常用的柵氧介質(zhì),基于高質(zhì)量AlN絕緣層材料制備工藝和優(yōu)化的界面預(yù)處理工藝,研制了高界面質(zhì)量的GaN基MIS-HEMT器件,并利用等效電路和解析模型對其界面特性進(jìn)行了定量表征。論文的主要研究成果包括：(1)采用等離子增強(qiáng)原子層沉積技術(shù)在低溫下制備了高質(zhì)量的AlN絕緣層材料。采用TMA和NH3作為反應(yīng)前驅(qū)體源,通過優(yōu)化前驅(qū)體脈沖時間、吹掃時間、RF功率等工藝參數(shù),在100℃-300℃工藝溫度范圍內(nèi)實現(xiàn)了AlN薄膜的自限制飽和生長。A1N薄膜沉積速率約為0.081nm/cycle,實現(xiàn)了原子尺度上的膜厚精確控制。通過優(yōu)化工藝溫度,在300℃下得到了光學(xué)禁帶寬度為5.8eV、表面粗糙度RMS小于0.5nm的AlN薄膜。XPS測試結(jié)果顯示,PEALD沉積AlN薄膜中氧雜質(zhì)原子含量處于13%的較低水平,Al/N原子比為1.6。AlN薄膜中不含碳雜質(zhì),說明優(yōu)化的沉積工藝有效避免了TMA前驅(qū)體中的碳原子嵌入。快速熱退火處理使薄膜結(jié)構(gòu)和電學(xué)特性進(jìn)一步改善,優(yōu)化的退火溫度范圍是450℃。(2)開發(fā)并優(yōu)化了GaN基MIS-HEMT器件的低損傷界面預(yù)處理技術(shù)和表面鈍化工藝。HF溶液處理使AlGaN/GaN異質(zhì)結(jié)方阻顯著減小,但是導(dǎo)致歐姆接觸特性惡化,所以本論文采用對溝道和歐姆接觸影響不大的KOH堿溶液化學(xué)清洗工藝。Hall測試表明,KOH溶液清洗、N2等離子體處理、02/N2等離子體處理分別使2DEG密度升高10%,遷移率降低10-20%；NH3/N2等離子體處理過程,含氫基團(tuán)使2DEG密度降低約10%,遷移率提高約10%。基于表面處理結(jié)果優(yōu)化了MIS-HEMT器件的原位界面預(yù)處理工藝,確定NH3/N2等離子體預(yù)處理可以使器件獲得最優(yōu)的界面和溝道輸運特性。研究了10nm表面鈍化層對異質(zhì)結(jié)溝道特性的影響,Hall測試顯示PEALD沉積、ALD沉積PECVD沉積SiN分別使異質(zhì)結(jié)方阻減小10%以上。拉曼測試表明鈍化層對異質(zhì)結(jié)應(yīng)力作用很小,溝道輸運特性變化來源十表而調(diào)制作用。A1203鈍化層中含有-OH基團(tuán),ON使界面態(tài)和2DEG面密度增大;A1N和SiN生長過程中有NH3參與反反應(yīng),表面施主態(tài)減少導(dǎo)致2DEG密度降低20%-50%,遷移率提高至原來的2倍,且AlN飩化層的表面調(diào)制作用更強(qiáng)。脈沖測試表明AlN鈍化器件的電流崩塌量僅為6%,遠(yuǎn)遠(yuǎn)低于常規(guī)PECVD沉積SiN鈍化器件的26%,從而確定PEALD沉積AlN為最優(yōu)的表面鈍化層材料。(3)基于PEALD沉積AlN柵絕緣層和界面預(yù)處理技術(shù),研制了高界面質(zhì)量和溝道輸運特性的AlGaN/GaN MIS-HEMT器件。與肖特基柵HEMT相比,采用20nm厚Al20O柵絕緣層的MOS-HEMT器件Vth負(fù)向漂移5.2V,而采用AlN柵絕緣層的MIS-HEMT器件Vth僅負(fù)漂了0.8V。AlN柵絕緣層使絕緣柵異質(zhì)結(jié)構(gòu)的C-V測試Vth回滯電壓從0.6V減小至50mV以下,變頻C-V表明界面態(tài)密度從4.61×1012cm-2減小至2.78×1012cm-2。AlN柵絕緣層使GaN基絕緣柵HEMT器件溝道輸運特性和場效應(yīng)遷移率提高,0.5μm柵長器件的峰值跨導(dǎo)從203mS/mm提高到289mS/mm,甚至超過了肖特基柵器件的270mS/mm。AlN柵絕緣層有效改善了絕緣柵HEMT器件的頻率特性和穩(wěn)定性,與A1203柵絕緣層器件相比fr/fmax水平從10.8GHz/11.6GHz提高到13.4GHz/16.1GHz。研制的5nm-Al2O3/1nm-AlN超薄疊層介質(zhì)凹槽柵MIS-HEMT飽和輸出電流和峰值跨導(dǎo)分別為1.24A/mmm和413mS/mm,開關(guān)態(tài)電流比達(dá)到10-10。100μm凹槽柵MIS-HEMT器件的fr/fmax達(dá)到24GHz/102GHz,AB類工作條件下5GHz連續(xù)波輸出功率超過7W/mm,功率附加效率在40%以上。(4)建立了GaN基絕緣柵HEMT器件的界面電荷定量表征模型,并對AlN/勢壘層和A1203/勢壘層界面電荷進(jìn)行了對比分析。建立了GaN基絕緣柵異質(zhì)結(jié)構(gòu)的界面態(tài)等效電路模型,利用變頻電導(dǎo)法成功分離了異質(zhì)結(jié)界面和絕緣層/勢壘層兩個界面處的陷阱,且并聯(lián)電導(dǎo)譜線擬合方法比常用的C-V測試方法更精確,此方法得到了國際同行的高度評價。PEALD沉積A1N柵絕緣層與勢壘層之間界面態(tài)密度為0.97-2.2×1013cm-2eV-1,分布在導(dǎo)帶底以下0.45-0.67eV能級范圍；ALD沉積A1203柵絕緣層與勢壘層界面ON缺陷使陷阱能級變深為0.52-0.72eV,態(tài)密度增大到1.6-9.0×1013cm-2eV-1�；�于異質(zhì)結(jié)能帶結(jié)構(gòu)和界面電荷分布,建立了肖特基柵和絕緣柵異質(zhì)結(jié)構(gòu)的平帶電壓解析模型,比直接采用閡值電壓解析法更加準(zhǔn)確。A1203與勢壘層界面電荷密度高達(dá)8.98x1012cm-2,引起平帶電壓和閾值電壓負(fù)漂3.78V；而AlN絕緣層界面電荷密度為-1.18×1012cm-2,界面固定電荷密度極低,而以界面態(tài)為主導(dǎo),界面有效電荷導(dǎo)致平帶電壓正向漂移0.32V。
[Abstract]:Compared with the traditional Schottky gate HEMT, GaN based insulated gate HEMT devices can effectively reduce gate leakage current, and have broad application prospects in high performance microwave power amplifiers, high voltage switches and other applications. However, the serious interface problems between the gate insulation and nitride will cause the performance degradation and reliability of the devices. This paper innovatively uses the AlN gate insulating layer instead of the common gate oxygen medium. Based on the preparation technology of high quality AlN insulating material and the optimized interface pretreatment process, the GaN based MIS-HEMT device with high interface quality is developed, and the interface characteristics are quantitatively characterized by the equivalent circuit and the analytical model. The main achievements of this paper are as follows: (1) high quality AlN insulating material was prepared by plasma enhanced atomic layer deposition at low temperature. Using TMA and NH3 as the precursor of the reaction, the AlN film was realized by optimizing the process parameters such as the pulse time of the precursor, the blowing time and the RF power, and at the temperature range of -300 C at 100 degrees centigrade. The deposition rate of the self limiting saturated.A1N film is about 0.081nm/cycle, and the membrane thickness is precisely controlled at the atomic scale. By optimizing the process temperature, the.XPS test results of the AlN film with the optical band width of 5.8eV and the surface roughness RMS less than 0.5nm show that the oxygen impurity atom content in the PEALD deposited AlN thin film is at 13%. The lower level of the Al/N atom ratio is carbon free in the 1.6.AlN film. It shows that the optimized deposition process effectively avoids the carbon atom embedded in the precursor of TMA. Rapid thermal annealing can further improve the structure and electrical properties of the film, and the optimized annealing temperature range is 450. (2) the low damage of the GaN based MIS-HEMT device is developed and optimized. .HF solution treatment of interface pretreatment and surface passivation process reduces the square resistance of AlGaN/GaN heterojunction significantly, but leads to the deterioration of ohm contact characteristics. Therefore, the.Hall test of KOH alkali solution, which has little influence on the channel and ohm contact, shows that KOH solution cleaning, N2 plasma treatment, 02/N2 plasma The density of 2DEG increased by 10% and the mobility was reduced by 10-20%, and the NH3/N2 plasma treatment process, the hydrogen containing group reduced the 2DEG density by about 10%, and the mobility increased about 10%. based on the surface treatment results to optimize the in-situ interface pretreatment process of the MIS-HEMT device, and the NH3/N2 plasma pretreatment could make the device get the best interface. The influence of the passivation layer on the 10nm surface on the characteristics of the heterojunction channel is studied. The Hall test shows that the PEALD deposition and the ALD deposition of PECVD deposition SiN reduce the heterojunction square resistance by more than 10% respectively. The Raman test shows that the passivation layer has little effect on the heterojunction stress, the channel transport characteristics change from the ten table and the modulation action in the passive layer of the.A1203 passivation layer. With the -OH group, the density of the interface state and the 2DEG surface is increased by ON, and NH3 is involved in the reaction during the growth of A1N and SiN. The decrease of the surface donor state causes the 2DEG density to decrease 20%-50%, the mobility increases to 2 times that of the original, and the surface modulation of the AlN ton layer is stronger. The pulse test shows that the current collapse of the AlN passivation device is only 6%, far lower than that of the AlN passivation device. Conventional PECVD deposition of SiN passivation device 26%, thus determining PEALD deposition AlN as the best surface passivation material. (3) based on PEALD deposited AlN gate insulating layer and interface pretreatment technology, a AlGaN/GaN MIS-HEMT device with high interfacial mass and channel transport characteristics is developed. Compared with the Schottky gate HEMT, 20nm thick Al20O gate insulating layer The device Vth is negatively drifting 5.2V, while the MIS-HEMT device using the AlN gate insulating layer is only negatively bleaching the 0.8V.AlN gate insulating layer to reduce the C-V test Vth hysteresis voltage of the insulated gate heterostructure from 0.6V to below 50mV. The frequency conversion C-V indicates that the interface state density is reduced from 4.61 x 1012cm-2 to the 2.78 x grid insulation layer. The transmission characteristics and field effect mobility are improved. The peak transconductance of 0.5 mu m gate length device is increased from 203mS/mm to 289mS/mm, and even the 270mS/mm.AlN gate insulation layer of the Schottky gate device improves the frequency characteristics and stability of the insulated gate HEMT device, and the fr/fmax level is improved from the 10.8GHz/11.6GHz to the A1203 gate insulating layer to the 10.8GHz/11.6GHz. The MIS-HEMT saturated output current and peak transconductance of the 5nm-Al2O3/1nm-AlN super thin layer dielectric groove gate are 1.24A/mmm and 413mS/mm respectively. The switching state current ratio reaches fr/fmax to 24GHz/102GHz of 10-10.100 mu m grooves MIS-HEMT device, and the output power of the 5GHz continuous wave exceeds the output power under the AB class working condition, and the power additional is added. The efficiency is above 40%. (4) the quantitative characterization model of the interface charge of the GaN based insulated gate HEMT is established, and the interface charge of the AlN/ barrier layer and the A1203/ barrier layer is contrasted. The equivalent circuit model of the interface state of the GaN based insulated gate heterostructure is established, and the heterojunction interface and insulating layer / potential barrier are successfully separated by the frequency conversion conductance method. The traps at the two interfaces and the parallel conductance spectrum fitting method are more accurate than the common C-V testing methods. This method obtains the high evaluation of the.PEALD deposition A1N gate insulating layer and the barrier layer of 0.97-2.2 x 1013cm-2eV-1, which is distributed at the 0.45-0.67eV level below the bottom of the guide band, and ALD deposition A1203 gate. The ON defects at the boundary layer and the barrier layer make the trap energy level deep to 0.52-0.72eV, the density of States increases to 1.6-9.0 x 1013cm-2eV-1. based on the structure of the heterojunction energy band and the interface charge distribution. The analytical model of the flat band voltage of the Schottky grid and the insulated gate heterostructure is established, which is more accurate than the barrier voltage analytical method for the.A1203 and the barrier layer. The surface charge density is up to 8.98x1012cm-2, which causes the negative drift of the flat band voltage and the threshold voltage 3.78V, while the interface charge density of the AlN insulating layer is -1.18 x 1012cm-2, the fixed charge density at the interface is very low, and the interface state is the dominant factor in the interface state, and the flat band voltage is positive drift 0.32V..
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：TN386

【相似文獻(xiàn)】

相關(guān)期刊論文 前10條

1 白超;;寬禁帶Ⅱ-VI族材料生長及其對器件的影響[J];發(fā)光快報;1989年Z1期

2 盛柏楨;南京固體器件研究所第七、第八次科研成果鑒定會[J];半導(dǎo)體技術(shù);1982年02期

3 史慶藩,喻志遠(yuǎn);光控微波固體器件研究進(jìn)展[J];通信學(xué)報;1990年04期

4 ;西安電子科技大學(xué)“寬禁帶半導(dǎo)體材料與器件”教育部重點實驗室[J];技術(shù)與創(chuàng)新管理;2007年04期

5 葉立劍;南京固體器件研究所召開第十一次科研成果鑒定會——31項科研成果通過鑒定[J];固體電子學(xué)研究與進(jìn)展;1984年01期

6 沈玉全，，,王玉堂;有機(jī)光電子材料和器件研究進(jìn)展[J];高技術(shù)通訊;1994年02期

7 舒學(xué)鏞,何小樂;薄膜SOI器件和材料的研究和發(fā)展方向[J];微電子技術(shù);1994年05期

8 章從福;;長春應(yīng)用化學(xué)所OTFT器件研究取得突破[J];半導(dǎo)體信息;2007年02期

9 李德祿;馬杰;;聚合物AWG器件研究內(nèi)容綜述[J];中國科技信息;2011年12期

10 任國屋;12GHz GaAs FET放大器[J];固體電子學(xué)研究與進(jìn)展;1984年01期

相關(guān)會議論文 前3條

1 龔旗煌;胡小永;李智;古英;張家森;楊宏;;介觀光子學(xué)器件研究進(jìn)展[A];2008介觀光學(xué)及其應(yīng)用研討會論文集[C];2008年

2 曹鏞;;聚合物發(fā)光材料與器件研究的進(jìn)展[A];第九屆全國發(fā)光學(xué)術(shù)會議摘要集[C];2001年

3 童利民;;微納光纖及其器件研究進(jìn)展[A];2008介觀光學(xué)及其應(yīng)用研討會論文集[C];2008年

相關(guān)重要報紙文章 前2條

1 本報記者 操秀英;進(jìn)軍多學(xué)科前沿交叉新領(lǐng)域[N];科技日報;2010年

2 唐婷邋徐玢;探索在下一代電子器件發(fā)展最前沿[N];科技日報;2007年

相關(guān)博士學(xué)位論文 前10條

1 孟繁新;碳基納米器件光電特性研究和金屬材料中氦原子行為研究[D];復(fù)旦大學(xué);2014年

2 祝杰杰;氮化物MIS-HEMT器件界面工程研究[D];西安電子科技大學(xué);2016年

3 委福祥;新型高性能有機(jī)電致發(fā)光器件的研究[D];上海大學(xué);2007年

4 郭鵬;有機(jī)電雙穩(wěn)材料與器件的研究[D];復(fù)旦大學(xué);2007年

5 楊樹威;新型自供能電致變色材料和器件的探索及研發(fā)[D];中國科學(xué)技術(shù)大學(xué);2013年

6 張曉波;染料摻雜的有機(jī)電致磷光/白光器件研究[D];上海大學(xué);2007年

7 劉向;有機(jī)薄膜晶體管及微腔頂發(fā)射有機(jī)發(fā)光器件的研究[D];上海大學(xué);2007年

8 胡仕剛;超薄柵氧MOS器件柵泄漏電流研究[D];西安電子科技大學(xué);2009年

9 劉舉慶;石墨烯基導(dǎo)電薄膜及其有機(jī)半導(dǎo)體二極管器件的制備與性能研究[D];南京郵電大學(xué);2011年

10 王蜀霞;有機(jī)半導(dǎo)體LPPP發(fā)光性質(zhì)及相關(guān)問題研究[D];重慶大學(xué);2002年

相關(guān)碩士學(xué)位論文 前10條

1 黃宇;1.2kV SiC MOSFET器件設(shè)計及可靠性研究[D];東南大學(xué);2015年

2 楊旭;Ge MOS界面調(diào)控與器件工藝集成研究[D];東南大學(xué);2015年

3 張桐碩;基于氧化鋅納米晶的紫外光電器件研究[D];沈陽師范大學(xué);2016年

4 王青松;InP基器件金屬接觸研究[D];蘇州大學(xué);2016年

5 于志浩;二維半導(dǎo)體器件電子輸運性質(zhì)研究[D];南京大學(xué);2015年

6 魏彩紅;苯并噻二唑—苯胺—芴類聚合物的合成和發(fā)光性能研究[D];華南理工大學(xué);2010年

7 湯振森;TiO_2阻變器件導(dǎo)電機(jī)理及其抗總劑量輻照性能研究[D];國防科學(xué)技術(shù)大學(xué);2013年

8 胡貴州;原位生長介質(zhì)層MIS-HEMT器件的研究[D];西安電子科技大學(xué);2010年

9 趙連鋒;高k介質(zhì)/金屬柵銻化鎵MOS器件關(guān)鍵技術(shù)研究[D];清華大學(xué);2014年

10 陽斌;Cu氧化物薄膜及納米線器件的電阻開關(guān)特性研究[D];暨南大學(xué);2015年

本文編號：2074202