• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Defects and electrical properties in Al-implanted 4H-SiC after activation annealing?

    2019-11-06 00:45:00YiDanTang湯益丹XinYuLiu劉新宇ZhengDongZhou周正東YunBai白云andChengZhanLi李誠瞻
    Chinese Physics B 2019年10期
    關(guān)鍵詞:正東白云

    Yi-Dan Tang(湯益丹),Xin-Yu Liu(劉新宇),Zheng-Dong Zhou(周正東),Yun Bai(白云),and Cheng-Zhan Li(李誠瞻)

    1High-Frequency High-Voltage Devices and Integrated Circuits Research and Development Center,Institute of Microelectronics of Chinese Academy of Sciences,Beijing 100029,China

    2University of Chinese Academy of Sciences,Beijing 100049,China

    3Zhuzhou CRRC Times Electric Co.,Ltd,Zhuzhou 412001,China

    Keywords:Al-implanted 4H-SiC,activation annealing,extended defects,carbon vacancies

    1.Introduction

    Semiconductor material,SiC,is attractive for the applications in high power,high temperature,high frequency,and high reliability device due to its exceptional properties.[1–8]Ptype doping of 4H-SiC using ion implantation and high temperature activation annealing is the key process in the fabrication of SiC devices.[2,3]Compared with boron(B),aluminum(Al)has a shallow acceptor level and a strong tendency to occupy atomic sites in the silicon(Si)sublattice,which makes Al+ion implantation more suitable for the production of heavily doped layers.[9–14]However,a great challenge exists in the effective doping of Al,because high energy of Al ion implantation inevitably produces defects and lattice disorder. Although redistribution of the implanted dopants and partial ion-induced damages can be reduced by high temperature implantation followed by high temperature annealing,not all the damages could be annealed out by higher temperature annealing,such as residual damages(distortion of lattice,vacancies and interstitials)and extended defects,because of dynamic defect recovery and generation in the activation annealing process.[13–26]And it was reported that the formation of extended defects in the implanted layers and the interfacial dislocations of the ion-implanted layer can occur in the annealing process.[15,20,23]Such high residual damages and extended defects of the implanted layers will greatly affect the electrical performance and reliability of SiC device,such as the mobility in MOSFETs and leakage current in PIN diodes.How to suppress the generation and distribution of these defects is still an open issue in the study of this subject.Therefore,a clearer understanding of the recovery,formation and distribution of the defects in the Al-implanted layers during the implantation and annealing processing is beneficial to obtaining the better electrical properties in Al-implanted 4H-SiC through optimization of activation annealing conditions.

    In this paper,the defects and electrical properties in Alimplanted 4H-SiC after high-temperature activation annealing(1600?C–1800?C)are investigated. The ion implantationinduced damages and the extended defects after the annealing process are investigated by using Rutherford backscattering spectroscopy(RBS/C),secondary ion mass spectroscopy(SIMS),transmission electron microscopy(TEM)analyses.The optimized activation annealing conditions are achieved,under which the lower defects and acceptable electrical properties are achieved and demonstrated by the Hall effect measurement.

    2.Experiment

    Multiple-energy Al implantations were performed on ntype,4?off the(0001)oriented 4H-SiC epilayer at a doping concentration of 1×1016cm?3. Hot implantation(500?C)was used to hinder amorphization and improve the quality of crystalline in Al-implanted 4H-SiC.As seen from Fig.1(a),the implantation at energy ranging from 30 keV to 300 keV with a total dose of 8.41×1014cm?2formed a box-like doping profile with a 6-nm-thick sacrificial oxidation silicon dioxide(SiO2)layer. And the obtained doping concentration of Ct=2×1019cm?3with a depth of about 320 nm after removing a 60-nm-thick sacrificial oxidation SiO2layer was characterized by SIMS measurement as shown in Fig.1(b).

    Fig.1. (a)Simulated concentration versus depth profiles of Al atoms after multiple energy implantations into SiC with the purpose of forming a box-like profile by using the Silvaco TCAD,and(b)doping concentration profiles measured by SIMS after removing 60-nm-thick sacrificial oxidation SiO2 layer.

    Post-implantation annealing was processed at 1600?C–1800?C with a protective carbon capping layer. Effects on Al ion implantation on n-type 4H-SiC followed by annealing at various temperatures was studied by using RBS/C,SIMS,TEM,and atomic force microscope(AFM)analyses.Transmission line model(TLM)and Hall effect measurements are also conducted to analyze the electrical properties.

    3.Results and discussion

    3.1.Defects analysis

    As one of the most common surface analytical techniques,Rutherford backscattering spectrometry along a low index crystallographic direction or channel(RBS/C)is sensitive to very small atomic displacements from the crystalline lattice sites. The RBS/C interaction yield is strongly influenced by the crystal disorder and crystal orientation,which makes the technique unique for the analysis of ion implantation damage in single-crystal films and wafers.As shown in Fig.2,A,B,and C represent three relationships between location and the status of damages with the RBS/C from surface to inner region.The energy of backscattering atoms of A have little energy loss and most of ion-beams can be channeled,indicating A is near the surface and has good order lattice.B has an obvious peak,which indicates that many dislocation atoms or disorder lattices exist under the surface;C is the inner part of the crystal,which contains the damage status of C and the effect of B.The high yield in C is mainly due to a mass of dislocation atoms,containing the distortion lattice of C and the little random atoms of B.

    Fig.2.Relationship between the location and the status of damages with RBS/C.

    The Xminrefers to the ratio of the channeled intensity to the random intensity in the region just below the surface scattering peak.It yields information about the crystallinity in the near surface of the sample(the first 3 nm–15 nm in depth),which is related to the surface damage,contamination and the existence of oxides.Figure 3 shows the Xminvalues of samples before and after thermal implantation annealing at various temperatures(1600?C–1800?C)for 15 min.Each of all the annealed samples has a smaller Xminvalue than that of the asimplanted(Xmin=0.403)and the Xminvalue decreases with annealing temperature rising up.With the annealing temperature higher than 1700?C,the sample’s surface damage can be effectively reduced.

    Fig.3. Variation of Xmin(160?detector)with temperature of implanted samples before and after activation annealing for 15 min.

    From Figs.4(a)–4(c),all the samples of SiC samples can be channeled,and the channeling yield increases with channel number decreasing without obvious damage peaks,which do not reach the random level. The crystal has no obvious amorphous layer and the experimentally obtained RBS spectra after annealing are closely identical to the fresh virgin spectrum. It can be concluded that the use of hot temperature(500?C)implantation can avoid forming the high-density extended defects,dopant redistribution,and surface decomposition in the implanted layer.However,corresponding to the random spectra,a defective layer containing a low level of lattice displacement or distortion is formed on the implanted sample in Fig.4(a).

    In the amplified regions on the right in Figs.4(b)and 4(c),the densities of defects near surface under all the annealing conditions except for the sample of 1600?C for 15 min,are lower than that of the as-implanted one,which proves that the defects near-surface region are greatly affected by annealing temperature.However,for the annealing time of 15 min,the defects near the bottom of the ion-implanted layer for each of all annealing samples are more than those of as-implanted sample at the different temperatures(from 1600?C–1800?C),indicated by the through RBS/C analysis results as shown in Fig.4(b).

    In order to reduce the defects both near the surface and bottom of the ion-implanted layer in high temperature annealing process,the annealing is carried under the conditions of 1800?C for 5 min and 15 min.It is shown in the amplified region on the right in Fig.4(c)that the damages near the surface and the bottom of the sample annealed for 1800?C and 15 min are more pronounced than for 1800?C and 5 min.Furthermore,as seen in Fig.4(c),the density of defects near the bottom region under the annealing condition of 1800?C for 15 min is higher than that of the as-implanted one,but not under the condition of 1800?C and 5 min.It may be because the longer time thermal annealing induces new extended defects near the bottom of the ion-implanted layers. Therefore,the annealing time is another key factor affecting the generation of extended defects.

    Fig.4.Overlays of implanted samples(a)before and(b)after activation annealing at various temperatures for 15 min and(c)at 1800 ?C and different annealing times.

    In Fig.5,all samples are tested after removing protective carbon capping layer and sacrificial oxidation. Profiles of implanted atoms before and after annealing at 1800?C,15 min,and 5 min by SIMS do not coincide with each other near the bottom of the ion-implanted layer.Possible reasons are that the defect agglomeration and dopant redistribution occur near the bottom of the ion-implanted layer in the annealing process. This is consistent with the conclusion that the defects near the bottom of the ion-implanted layer will be dynamically restored and generated in the activation annealing process.Therefore,it is necessary to optimize the annealing conditions to minimize the defects near the bottom of the ionimplanted layer.As shown in the amplified area of Fig.5,the curve of the sample obtained under the activation annealing condition(1800?C/5 min)is highly coincident with that near the bottom of the as-implanted sample.

    Fig.5.Profiles of implanted atoms before and after annealing at 1800 ?C,15 min/5 min by SIMS after removing protective carbon capping layer and 60-nm-thick sacrificial oxidation SiO2 layer.

    From the above results of the RBS-C technique,we find quite a low level of the residual disorders and extended defects in the implanted and annealed SiC layers.As a complement to RBS/C,cross section samples in the implanted region are prepared.And the lattice structure of the implanted layer and the annealed layerare also measured with TEM,which is equipped with an FEI Talos F200 transmission electron microscope at 200 kV.The samples for TEM are cross-sectioned,prepared by focused ion beam(FIB).

    Figures 6(a)and 6(b)show cross-sectional[100]bright field-electron(BF)micrographs of identically Al-implanted samples with the annealing temperature at 1800?C for 15 min and 5 min,respectively.As seen from Figs.6(a)and 6(b),the visible depths of the damage areas are 445 nm and 467 nm respectively.From the above SIMS test data,it can be inferred that the damage areas include ion implantation region and part of trailing region.In Fig.6,all of the extended defects are visible in the Al-implanted region after 1800?C/5 min annealing and 1800?C/15 min annealing,especially near the bottom of Al-implanted region.These defects are lettered from A to C,which are polygonal loops differing in size.These loops form a network of almost orthogonal trace. Defect A is smallest,next is defect B.In the case of defect C,it is possible to demonstrate that it has a complex structure related to dislocations or carbon vacancy agglomerates.[19–24]The distribution of these defects is not uniform and appears to peak in a buried region close to the end of the Al-implanted region,which is between the bottom of implanted Al region and the unimplanted substrate.The defects of 1800?C/15 min sample(Fig.6(a))are obviously more than those of the sample with 1800?C/5 min(Fig.6(b)).This indicates that the longer annealing time will lead to more extended defects at the same temperature,which is in good agreement with the RBS analysis results.As shown in the amplified defects area in Figs.7(b)and 7(c),there are many polygonal dislocation loops with different sizes. The micrograph indicates that most of the defects at the bottom of implanted Al layers created during annealing are dislocations as indicated by arrows in Fig.7(c).The formation of these dislocations may be related to a cluster of C-related defects,such as carbon vacancies.[19–26]

    Fig. 6. Cross-sectional micrograph in Al-implanted region by (a)1800 ?C/5 min annealing and(b)1800 ?C/15 min annealing.

    Fig.7.Cross-sectional micrograph in Al-implanted region by 1800 ?C/5 min annealing.

    Fig.8.Defect model in Al-implanted 4H-SiC layer.

    To obtain the mechanisms responsible for the formation and elimination of extended defects,according to the previous defect theory,[15,21–23]the defect model in Al-implanted 4HSiC layer is also investigated.The high temperature activation annealing is the process of replacing the implanted Al atoms with Si.During the activation annealing,most of dopants are activated,and the ion-induced damages are recovered because of the recrystallization of the annealed samples.As seen from Fig.8,in the high temperature activation annealing process,the persistent carbon vacancies in the drift layers after epitaxy can be effectively recombined by the excess carbon interstitials Cicreated by implation.At the same time,new carbon vacancies will be formed in the high temperature process.So,the optimization of annealing conditions can be realized by controlling the generation and elimination of carbon vacancy(VC)density in the ion implanted layers.

    3.2.Electrical and surface property analysis

    As seen from Table 1,the Hall hole density P,Hall mobilityμand electrical activation ratio A(A=P/Ct)are improved by increasing annealing temperature through using Pensl et al.’s Hall scattering factor. Sheet resistance R and specific contact resistance(SCR)decrease with annealing temperature increasing.As the temperature increases,the rate of annealing activation increases.At the same annealing temperature,the longer time annealing can improve the electrical activation properties effectively.However,the consideration of the lower defects,the sample annealed at 1800?C/5 min shows relatively good electrical properties.

    Table 1.Values obtained by Hall-effect and TLM measurements for p-type 4H-SiC samples at room temperature(RT).

    Furthermore, the surface roughness values of Alimplanted samples before and after activation annealing at various temperatures are measured by AFM.We use the 5-point average of the large area implantation and activation annealing sample.The results in Table 2 show that the average surface roughness values increase slightly from 0.058 nm to 0.110 nm after Al hot implantation,the surface deterioration may be due to the Al implantation.After annealing at 1600?C–1800?C for 15 min,the discontinuity of surface is not obviously raised,which is below 0.304 nm.The surface step-bunching is effectively suppressed and the surface roughness values of all the samples are not obviously deteriorated,which is due to the existence of an effective protective carbon capping layer.

    Table 2.Average surface roughness values of Al-implanted 4H-SiC followed by annealing at various temperatures.

    4.Conclusions

    The defects and electrical properties in Al-implanted 4HSiC after activation annealing(1600?C–1800?C)are investigated. High temperature annealing can reduce the ion implantation-induced damage effectively,but it may induce extended defects at the same time.How to suppress the generation and distribution of the defects is very critical. According to Xminand RBS/C analysis,the ion implantationinduced surface damage could be effectively reduced by annealing at temperatures higher than 1700?C,demonstrating that the damage near the surface region is greatly affected by annealing temperature.However,the effect of annealing temperature on the suppression of the defects near the bottom region is not obvious.The longer thermal annealing time(such as 15 min)may induce new extended defects near the bottom of the ion-implanted layers,which is mainly due to dynamic defect recovery and generation in the activation annealing process.Therefore,the annealing time is another key factor influencing the generation of extended defects.

    From the RBS/C,SIMS,TEM,and defect model analysis,two sources of the residual defects are existent in the ion-implanted layer after annealing:one is the defects generated in ion implantation process,which cannot be completely annealed out by high temperature annealing process,and the other is the extended defects induced during activation annealing,especially for the longer activation annealing time. It can be inferred that the generation and elimination density of extended defects in the ion implanted devices are closely related to annealing conditions. The surface roughness values of all the samples after annealing are not obviously deteriorated due to the existence of an effective protective carbon capping layer.The optimized activation annealing conditions of 1800?C/5 min are achieved,and thus the lower defects(near the surface and bottom region)and acceptable electrical properties are obtained,which are conducive to the application of numerous SiC-based devices.

    猜你喜歡
    正東白云
    Design and Development of Garment Fabric Database Management System
    三塔四跨鋼-混凝土結(jié)合梁懸索橋成橋荷載試驗(yàn)研究
    白云(外三首)
    天津詩人(2017年2期)2017-11-29 01:24:14
    陜西省咸陽市教學(xué)能手——陳正東
    棒棒糖
    尋找丟失的快樂
    兒子簽下替母還款保證是否有效
    女性天地(2015年10期)2015-04-29 00:44:03
    白云的來歷
    我喜歡白云
    滇池(2014年5期)2014-05-29 07:32:31
    白云
    国产 一区 欧美 日韩| 国产精品综合久久久久久久免费| 最新中文字幕久久久久| 俄罗斯特黄特色一大片| 很黄的视频免费| 高潮久久久久久久久久久不卡| 少妇熟女aⅴ在线视频| 在线观看av片永久免费下载| 亚洲内射少妇av| 欧美在线一区亚洲| 两人在一起打扑克的视频| 真实男女啪啪啪动态图| 一级黄色大片毛片| 婷婷六月久久综合丁香| 天天躁日日操中文字幕| 色尼玛亚洲综合影院| 在线观看舔阴道视频| ponron亚洲| 深夜精品福利| 日本一二三区视频观看| 怎么达到女性高潮| 国产免费一级a男人的天堂| 黄片小视频在线播放| 色精品久久人妻99蜜桃| 中文在线观看免费www的网站| h日本视频在线播放| 亚洲欧美日韩无卡精品| 亚洲欧美日韩卡通动漫| 亚洲第一欧美日韩一区二区三区| 成人高潮视频无遮挡免费网站| 日韩欧美精品v在线| 最近视频中文字幕2019在线8| 两个人视频免费观看高清| 女人十人毛片免费观看3o分钟| 99国产精品一区二区蜜桃av| 亚洲av第一区精品v没综合| 欧美xxxx黑人xx丫x性爽| 免费人成视频x8x8入口观看| 欧美zozozo另类| 国产精品 国内视频| 精品欧美国产一区二区三| 国产精品美女特级片免费视频播放器| 国产真实乱freesex| 99riav亚洲国产免费| 一边摸一边抽搐一进一小说| 青草久久国产| 亚洲最大成人手机在线| 一边摸一边抽搐一进一小说| 成人性生交大片免费视频hd| 在线免费观看不下载黄p国产 | 国产乱人伦免费视频| 成人国产综合亚洲| 亚洲国产精品合色在线| 国语自产精品视频在线第100页| 国产伦精品一区二区三区四那| 99热这里只有精品一区| 18禁黄网站禁片午夜丰满| av女优亚洲男人天堂| 中亚洲国语对白在线视频| 日本一二三区视频观看| 最近最新免费中文字幕在线| 叶爱在线成人免费视频播放| 国产一区二区在线av高清观看| 成年女人永久免费观看视频| 亚洲黑人精品在线| 国产精品美女特级片免费视频播放器| 欧美极品一区二区三区四区| 成人欧美大片| 欧美不卡视频在线免费观看| 久久久久久人人人人人| 成年版毛片免费区| av在线蜜桃| 人妻夜夜爽99麻豆av| 国产野战对白在线观看| 国产不卡一卡二| 色吧在线观看| 中文字幕熟女人妻在线| 免费观看人在逋| 俄罗斯特黄特色一大片| 午夜福利在线观看吧| 久久精品91无色码中文字幕| 亚洲av熟女| 嫩草影院入口| 成人性生交大片免费视频hd| 欧美另类亚洲清纯唯美| 国产亚洲精品一区二区www| 中文字幕久久专区| 最好的美女福利视频网| 色播亚洲综合网| 精品久久久久久成人av| 精品一区二区三区视频在线观看免费| 亚洲av电影在线进入| 桃色一区二区三区在线观看| 国产精品99久久99久久久不卡| 一进一出好大好爽视频| 男人的好看免费观看在线视频| 99热这里只有是精品50| 嫩草影视91久久| 久久久国产精品麻豆| 亚洲av免费高清在线观看| 可以在线观看的亚洲视频| 最近在线观看免费完整版| av片东京热男人的天堂| 亚洲欧美激情综合另类| 在线看三级毛片| 国产精品久久电影中文字幕| 看片在线看免费视频| www日本在线高清视频| 黄色成人免费大全| 日韩中文字幕欧美一区二区| 亚洲 国产 在线| 97人妻精品一区二区三区麻豆| 丰满的人妻完整版| 国产精品爽爽va在线观看网站| 亚洲五月天丁香| 99久久无色码亚洲精品果冻| tocl精华| 欧美一级毛片孕妇| 午夜精品一区二区三区免费看| 脱女人内裤的视频| 99久久99久久久精品蜜桃| 日韩欧美在线乱码| 无限看片的www在线观看| 变态另类成人亚洲欧美熟女| 老熟妇仑乱视频hdxx| 男女做爰动态图高潮gif福利片| 哪里可以看免费的av片| 日本a在线网址| 一进一出抽搐动态| 国产av一区在线观看免费| 成人欧美大片| 欧美精品啪啪一区二区三区| 精品人妻1区二区| 国产一区在线观看成人免费| 亚洲熟妇中文字幕五十中出| 亚洲欧美日韩卡通动漫| 欧美日韩一级在线毛片| 国产精品久久久久久久久免 | 国产亚洲欧美在线一区二区| 老鸭窝网址在线观看| 国产精华一区二区三区| 亚洲人与动物交配视频| 高清在线国产一区| 好看av亚洲va欧美ⅴa在| 在线观看免费视频日本深夜| 久久久久亚洲av毛片大全| 国产91精品成人一区二区三区| or卡值多少钱| av视频在线观看入口| 欧美色视频一区免费| 老司机午夜福利在线观看视频| 中文字幕av在线有码专区| 国产精品亚洲美女久久久| 精品国产亚洲在线| 日本五十路高清| 在线观看一区二区三区| 九色成人免费人妻av| 欧美性猛交黑人性爽| 精品久久久久久久毛片微露脸| 在线天堂最新版资源| 99久久99久久久精品蜜桃| 又紧又爽又黄一区二区| 国产成人系列免费观看| 欧美黄色片欧美黄色片| 男女之事视频高清在线观看| 麻豆国产av国片精品| 桃色一区二区三区在线观看| 欧美大码av| 久久久久国产精品人妻aⅴ院| av在线蜜桃| 久久精品国产自在天天线| 九色成人免费人妻av| 亚洲黑人精品在线| 日本在线视频免费播放| 可以在线观看毛片的网站| 久久国产精品影院| 亚洲美女视频黄频| 国产黄色小视频在线观看| 青草久久国产| 性欧美人与动物交配| 日日夜夜操网爽| 波野结衣二区三区在线 | 亚洲熟妇中文字幕五十中出| 丝袜美腿在线中文| 亚洲人与动物交配视频| 国产真实乱freesex| 日本一本二区三区精品| 亚洲av中文字字幕乱码综合| 国语自产精品视频在线第100页| 婷婷精品国产亚洲av在线| 国产高清激情床上av| 亚洲精品美女久久久久99蜜臀| 香蕉丝袜av| 性色avwww在线观看| 国产单亲对白刺激| 人人妻人人看人人澡| 亚洲精品一卡2卡三卡4卡5卡| 欧美在线黄色| 国产一区二区三区在线臀色熟女| 99精品久久久久人妻精品| 欧美中文综合在线视频| 在线播放无遮挡| 欧美三级亚洲精品| 午夜福利18| 亚洲精品美女久久久久99蜜臀| 一个人观看的视频www高清免费观看| 男人和女人高潮做爰伦理| 97超级碰碰碰精品色视频在线观看| 国产在线精品亚洲第一网站| 又黄又爽又免费观看的视频| 最好的美女福利视频网| av欧美777| 欧美一区二区国产精品久久精品| 日韩欧美精品免费久久 | 毛片女人毛片| 中文字幕人妻熟人妻熟丝袜美 | 成人特级av手机在线观看| 51国产日韩欧美| 搡老妇女老女人老熟妇| а√天堂www在线а√下载| 97超级碰碰碰精品色视频在线观看| 国内久久婷婷六月综合欲色啪| 黄色丝袜av网址大全| 成人永久免费在线观看视频| ponron亚洲| 亚洲精品成人久久久久久| 国产精品日韩av在线免费观看| 男女视频在线观看网站免费| 老司机福利观看| 国产伦在线观看视频一区| 一区二区三区高清视频在线| 欧美黄色片欧美黄色片| 国产精品 国内视频| 国产精品久久久久久久久免 | 国产麻豆成人av免费视频| 国产色婷婷99| 国产高清视频在线播放一区| 床上黄色一级片| 热99re8久久精品国产| 免费看光身美女| 麻豆国产97在线/欧美| 99热这里只有精品一区| 精品人妻1区二区| 欧美乱妇无乱码| 久久久久国产精品人妻aⅴ院| 国产精品日韩av在线免费观看| 国内久久婷婷六月综合欲色啪| 国产精品影院久久| 精品熟女少妇八av免费久了| 亚洲精品在线美女| 女人十人毛片免费观看3o分钟| 麻豆一二三区av精品| 国产精品久久久久久精品电影| 美女高潮的动态| 老汉色∧v一级毛片| 丝袜美腿在线中文| 国产午夜精品论理片| 亚洲18禁久久av| 一卡2卡三卡四卡精品乱码亚洲| 大型黄色视频在线免费观看| 久久午夜亚洲精品久久| 九九在线视频观看精品| 在线观看美女被高潮喷水网站 | 日韩国内少妇激情av| 国产一区二区激情短视频| 尤物成人国产欧美一区二区三区| 亚洲自拍偷在线| 国产精华一区二区三区| 波多野结衣巨乳人妻| 午夜福利在线在线| 亚洲国产欧美人成| 十八禁人妻一区二区| 亚洲av电影不卡..在线观看| 国产精品国产高清国产av| 成人三级黄色视频| 天美传媒精品一区二区| 成人鲁丝片一二三区免费| 国产成+人综合+亚洲专区| av天堂在线播放| 久久久久久国产a免费观看| 在线观看日韩欧美| 真人做人爱边吃奶动态| 国产亚洲精品久久久久久毛片| 久久亚洲精品不卡| 岛国在线免费视频观看| 99久久成人亚洲精品观看| 一区二区三区激情视频| 18禁在线播放成人免费| 亚洲avbb在线观看| 国内精品美女久久久久久| 淫秽高清视频在线观看| 很黄的视频免费| 又紧又爽又黄一区二区| 天堂动漫精品| 国产69精品久久久久777片| 亚洲国产精品合色在线| 一区福利在线观看| 久久性视频一级片| 怎么达到女性高潮| 亚洲成人精品中文字幕电影| 天天添夜夜摸| 99热6这里只有精品| 麻豆一二三区av精品| 国产真实伦视频高清在线观看 | 两个人的视频大全免费| 偷拍熟女少妇极品色| 老司机福利观看| 国产极品精品免费视频能看的| 丰满乱子伦码专区| 欧美丝袜亚洲另类 | 成人性生交大片免费视频hd| 一级毛片高清免费大全| 丰满的人妻完整版| 一级作爱视频免费观看| 成年版毛片免费区| 岛国视频午夜一区免费看| 免费在线观看成人毛片| 亚洲中文字幕一区二区三区有码在线看| 欧美成人a在线观看| www日本在线高清视频| 国内毛片毛片毛片毛片毛片| 国产伦一二天堂av在线观看| av在线天堂中文字幕| av专区在线播放| 天堂动漫精品| 啦啦啦韩国在线观看视频| 美女高潮喷水抽搐中文字幕| 最新美女视频免费是黄的| 久久这里只有精品中国| 99久国产av精品| 午夜福利18| xxxwww97欧美| 2021天堂中文幕一二区在线观| 精品欧美国产一区二区三| 全区人妻精品视频| 18禁裸乳无遮挡免费网站照片| 免费无遮挡裸体视频| 一夜夜www| 欧美日本视频| 免费大片18禁| 搡老熟女国产l中国老女人| 国产一区二区激情短视频| 99精品在免费线老司机午夜| 十八禁网站免费在线| 日韩欧美国产在线观看| 国产精品,欧美在线| 级片在线观看| 国产精品免费一区二区三区在线| 尤物成人国产欧美一区二区三区| av欧美777| 精品日产1卡2卡| 国产真实伦视频高清在线观看 | 99在线视频只有这里精品首页| 在线天堂最新版资源| 一边摸一边抽搐一进一小说| 亚洲国产高清在线一区二区三| www.www免费av| 精品不卡国产一区二区三区| 亚洲五月婷婷丁香| 两个人的视频大全免费| 国产麻豆成人av免费视频| 日韩人妻高清精品专区| 国产成人av教育| 精品人妻偷拍中文字幕| 中文字幕精品亚洲无线码一区| 午夜福利高清视频| aaaaa片日本免费| 精品人妻1区二区| aaaaa片日本免费| 人人妻人人澡欧美一区二区| 久久精品国产99精品国产亚洲性色| 免费看a级黄色片| 成年免费大片在线观看| 精品久久久久久,| 国产单亲对白刺激| 一区福利在线观看| 亚洲成a人片在线一区二区| 精品国产亚洲在线| 亚洲av免费在线观看| 一本一本综合久久| 少妇的逼水好多| 一进一出好大好爽视频| 午夜激情欧美在线| 色老头精品视频在线观看| 高清日韩中文字幕在线| 亚洲欧美日韩高清专用| 香蕉久久夜色| 国产高清激情床上av| 可以在线观看的亚洲视频| 91在线观看av| eeuss影院久久| 操出白浆在线播放| 亚洲色图av天堂| 精品国产美女av久久久久小说| 午夜精品久久久久久毛片777| 成人国产综合亚洲| 一个人观看的视频www高清免费观看| 国产乱人伦免费视频| 免费搜索国产男女视频| 女同久久另类99精品国产91| 1024手机看黄色片| 好男人电影高清在线观看| 老司机午夜十八禁免费视频| 18禁黄网站禁片免费观看直播| 欧美一级毛片孕妇| 国产高清激情床上av| 天堂影院成人在线观看| АⅤ资源中文在线天堂| 国产亚洲精品综合一区在线观看| 精品免费久久久久久久清纯| 国产精品1区2区在线观看.| 俺也久久电影网| 欧美日韩黄片免| 午夜精品久久久久久毛片777| 精品人妻偷拍中文字幕| 国产精品亚洲av一区麻豆| www日本黄色视频网| 亚洲精品乱码久久久v下载方式 | 小蜜桃在线观看免费完整版高清| 深爱激情五月婷婷| 国产精品一区二区三区四区免费观看 | 国产69精品久久久久777片| 丁香欧美五月| 精品人妻一区二区三区麻豆 | 亚洲天堂国产精品一区在线| 少妇的逼好多水| 真人做人爱边吃奶动态| 国产伦人伦偷精品视频| 欧美最新免费一区二区三区 | 97超级碰碰碰精品色视频在线观看| 在线视频色国产色| 精品久久久久久久久久久久久| 免费电影在线观看免费观看| 看片在线看免费视频| 欧美一区二区亚洲| 亚洲精品一卡2卡三卡4卡5卡| 午夜福利视频1000在线观看| 嫩草影视91久久| 性欧美人与动物交配| 日本 av在线| xxx96com| 午夜福利免费观看在线| 欧美激情久久久久久爽电影| 免费观看的影片在线观看| 国产高潮美女av| 国内精品久久久久久久电影| 少妇丰满av| 国产色爽女视频免费观看| 女生性感内裤真人,穿戴方法视频| 亚洲国产日韩欧美精品在线观看 | 国产一区二区三区视频了| 国产成人aa在线观看| av中文乱码字幕在线| 欧美另类亚洲清纯唯美| 波多野结衣高清作品| 国产亚洲精品综合一区在线观看| 91久久精品国产一区二区成人 | 老鸭窝网址在线观看| 久久精品91蜜桃| 一进一出抽搐动态| 国产真实伦视频高清在线观看 | 精品无人区乱码1区二区| 丁香欧美五月| 两个人看的免费小视频| 久久久精品欧美日韩精品| 国产精品一区二区三区四区免费观看 | 国产成+人综合+亚洲专区| 最近最新中文字幕大全免费视频| 欧美区成人在线视频| 久久久国产成人免费| 精品国产亚洲在线| 亚洲成av人片免费观看| 日韩人妻高清精品专区| 色av中文字幕| 午夜a级毛片| 午夜福利成人在线免费观看| 色综合亚洲欧美另类图片| 国产激情欧美一区二区| 波多野结衣高清无吗| 在线免费观看不下载黄p国产 | 色尼玛亚洲综合影院| av欧美777| 一卡2卡三卡四卡精品乱码亚洲| 日韩欧美精品v在线| 桃色一区二区三区在线观看| 午夜福利在线在线| 国产中年淑女户外野战色| 日韩欧美 国产精品| 亚洲欧美日韩高清专用| 日本黄大片高清| 久久午夜亚洲精品久久| 精品一区二区三区视频在线观看免费| 十八禁人妻一区二区| 中文亚洲av片在线观看爽| 午夜福利在线观看吧| 又紧又爽又黄一区二区| a在线观看视频网站| 一区二区三区激情视频| 给我免费播放毛片高清在线观看| 夜夜看夜夜爽夜夜摸| 午夜福利在线观看吧| 波野结衣二区三区在线 | 一级黄片播放器| 欧美一区二区精品小视频在线| 精品欧美国产一区二区三| 九九在线视频观看精品| 性色avwww在线观看| 久久香蕉精品热| 一本久久中文字幕| 全区人妻精品视频| 国产亚洲精品久久久com| 精品一区二区三区视频在线观看免费| 国产精华一区二区三区| 夜夜看夜夜爽夜夜摸| 国产亚洲精品久久久com| 国产午夜福利久久久久久| 成年人黄色毛片网站| 国产免费一级a男人的天堂| 成人性生交大片免费视频hd| 久久久久久九九精品二区国产| 欧美日韩福利视频一区二区| 一进一出抽搐gif免费好疼| 女警被强在线播放| 亚洲精品亚洲一区二区| 97超级碰碰碰精品色视频在线观看| 女人高潮潮喷娇喘18禁视频| 亚洲国产中文字幕在线视频| 久久久久久国产a免费观看| 激情在线观看视频在线高清| 亚洲人成电影免费在线| 男女下面进入的视频免费午夜| 欧美最黄视频在线播放免费| 狠狠狠狠99中文字幕| 国产极品精品免费视频能看的| 女人被狂操c到高潮| 欧美黄色片欧美黄色片| 两性午夜刺激爽爽歪歪视频在线观看| 亚洲av免费高清在线观看| 丁香欧美五月| 99热精品在线国产| 亚洲黑人精品在线| 日韩精品青青久久久久久| 国产久久久一区二区三区| 国产精品日韩av在线免费观看| h日本视频在线播放| 国产成人av教育| 国产精品久久久久久精品电影| 亚洲午夜理论影院| 桃红色精品国产亚洲av| 亚洲国产精品sss在线观看| 午夜精品一区二区三区免费看| 51午夜福利影视在线观看| 身体一侧抽搐| 欧美成人免费av一区二区三区| 床上黄色一级片| 国产精品99久久99久久久不卡| 非洲黑人性xxxx精品又粗又长| 国产欧美日韩一区二区三| 搡老熟女国产l中国老女人| 青草久久国产| 亚洲精品成人久久久久久| 日日夜夜操网爽| 日本 欧美在线| 婷婷精品国产亚洲av在线| 九色国产91popny在线| 性色av乱码一区二区三区2| 亚洲成人久久性| 欧洲精品卡2卡3卡4卡5卡区| 中文字幕熟女人妻在线| 久久精品91蜜桃| 欧美成人免费av一区二区三区| 国产精品三级大全| 亚洲av二区三区四区| 少妇人妻精品综合一区二区 | 天天添夜夜摸| 国产99白浆流出| 一卡2卡三卡四卡精品乱码亚洲| 色综合站精品国产| 欧美区成人在线视频| 久久精品国产99精品国产亚洲性色| 国产国拍精品亚洲av在线观看 | 日韩欧美免费精品| 每晚都被弄得嗷嗷叫到高潮| svipshipincom国产片| 偷拍熟女少妇极品色| 1000部很黄的大片| 欧美国产日韩亚洲一区| 我要搜黄色片| ponron亚洲| 中文字幕人妻熟人妻熟丝袜美 | 成人特级黄色片久久久久久久| 久久草成人影院| 成年女人永久免费观看视频| 国产精品亚洲一级av第二区| 亚洲第一欧美日韩一区二区三区| 国产三级黄色录像| 女同久久另类99精品国产91| 亚洲第一欧美日韩一区二区三区| 琪琪午夜伦伦电影理论片6080| 中文亚洲av片在线观看爽| 91麻豆av在线| 淫秽高清视频在线观看| 欧美日韩黄片免| 亚洲精品乱码久久久v下载方式 | 女同久久另类99精品国产91| www国产在线视频色| 欧美一区二区国产精品久久精品| 在线天堂最新版资源| 老司机福利观看| 嫩草影院精品99| 色哟哟哟哟哟哟| 在线播放国产精品三级| 18禁美女被吸乳视频| 国产精品久久久久久亚洲av鲁大| 久久久精品大字幕|