未掺杂CdZnTe与掺铟CdZnTe晶体的热处理

对于未掺杂Cd0.9Zn0.1Te晶片,采用在Cd/Zn气氛下,以In作为气相掺杂源进行热处理;而对于低阻In-Cd0.9Zn0.1Te晶片,则采用在Te气氛下进行热处理.分别研究了不同的热处理条件,包括温度、时间、pIn或pTe等对晶片电学性能、红外透过率以及Te夹杂/沉淀相的影响.结果表明,在Cd/Zn气氛下适当的掺In热处理和在Te气氛下适当的热处理均有效地提高了晶片的电阻率,分别达到2.3×1010和5.7×109Ω·cm,同时晶片的其他性能也得到明显改善.     

未掺杂CdZnTe与掺铟CdZnTe晶体的热处理

对于未掺杂Cd0.9Zn0.1Te晶片,采用在Cd/Zn气氛下,以In作为气相掺杂源进行热处理;而对于低阻In-Cd0.9Zn0.1Te晶片,则采用在Te气氛下进行热处理.分别研究了不同的热处理条件,包括温度、时间、pIn或pTe等对晶片电学性能、红外透过率以及Te夹杂/沉淀相的影响.结果表明,在Cd/Zn气氛下适当的掺In热处理和在Te气氛下适当的热处理均有效地提高了晶片的电阻率,分别达到2.3×1010和5.7×109Ω·cm,同时晶片的其他性能也得到明显改善.     

CdZnTe材料的表面钝化新工艺

研究了一种新的钝化CdZnTe(CZT)器件表面的工艺,即先采用KOH-KCl溶液对CZT表面进行处理,再用NH4F/H2O2溶液对其进行表面氧化的二步法钝化工艺.并借助俄歇电子能谱(AES)、微电流测试仪等手段对其表面钝化层的质量进行了鉴别,同时与KOH-KCl和NH4F/H2O2两种工艺进行了比较.AES能谱分析表明,采用二步法工艺钝化,既可获得化学计量比较好的CZT表面,又可在表面形成一层起保护作用的氧化层.I-Ⅴ特性曲线显示,两步法钝化后CZT器件的漏电流与KOH-KCl和NH4F/H2O2钝化相比都有一定程度的下降.说明文中提出的新工艺在CZT器件制备方面具有良好的应用前景.     

CdZnTe材料的表面钝化新工艺

研究了一种新的钝化CdZnTe(CZT)器件表面的工艺，即先采用KOHKCl溶液对CZT表面进行处理，再用NH4F/H2O2溶液对其进行表面氧化的二步法钝化工艺．并借助俄歇电子能谱（AES）、微电流测试仪等手段对其表面钝化层的质量进行了鉴别，同时与KOH KCl和NH4F/H2O2两种工艺进行了比较．AES能谱分析表明，采用二步法工艺钝化，既可获得化学计量比较好的CZT表面，又可在表面形成一层起保护作用的氧化层．I-V特性曲线显示，两步法钝化后CZT器件的漏电流与KOH KCl和NH4F/H2O2钝化相比都有一定程度的下降．说明文中提出的新工艺在CZT器件制备方面具有良好的应用前景．     

光诱导化学汽相淀积（LCVD）技术的研究进展

光诱导化学汽相淀(?)(LCVD)技术是一种新的低温化薄膜制备技术.本文首先评述了LCVD技术的特点、原理和装置,然后着重讨论了利用这种技术制备金属、半导体与化合物和介质薄膜以及一些淀积规律,最后指出了LCVD技术尚待解决的若干问题.     

Effect of constrained growth on defect structures in microgravity grown CdZnTe boules

In a microgravity environment obtainable in an orbiting space shuttle, it is possible to virtually eliminate gravity related effects such as buoyancy driven convection and hydrostatic forces thus providing an ideal environment for diffusion-controlled, containerless crystal growth processes. Under such conditions, it is possible to investigate the effects of gravity independent growth parameters on crystal growth. Studies of CdZnTe boules grown on space shuttle mission USML-1 revealed that regions of the boules grown with wall contact were associated with a higher defect density than regions grown with partial or no wall contact. Defect densities in certain regions grown without wall contact were as low as 5 × 10²/cm² to 1.2 × 10³/cm². More detailed studies on the effects of wall contact were sought in the USML-2 mission. Two CdZnTe boules (GCRC-1 and GCRC-2) were grown by the seeded Bridgman-Stockbarger method. Boule GCRC-1 was grown under constrained conditions to force full wall contact while boule GCRC-2 had a tapered geometry designed to minimize wall contact. Defect distributions in the boules were investigated by synchrotron white beam x-ray topography. The sample GCRC-1 was characterized by the presence of large inhomogeneous strains, numerous grains and twins, all of which are caused by effects related to wall contact. On the other hand, a part of the boule GCRC-2 that grew free from wall contact revealed minimum surface strains, the absence of twins and a very high structural uniformity. Results clearly verify that ampoule wall contact plays an important role in determining the incidence of crystal imperfections.     

Metalorganic vapor phase epitaxy of (100) CdZnTe layers using diisopropylzinc source

Growth characteristics of (100) Cd_1−xZn_xTe (CZT) have been studied using metalorganic vapor phase epitaxy. CZT layers were grown on (100) GaAs substrates using diisopropylzinc (DiPZn), dimethylcadmiun (DMCd), and diethyltelluride (DETe) as precursors. Growths were carried out in the temperature range from 375 to 450°C. Since DiPZn has lower vapor pressure than DMCd, CZT layers with Zn composition below 0.06 were grown with good compositional control. Layers with uniform Zn composition and thickness over an area of 10 × 15 mm² were grown. Enhancement of CZT growth rate was observed when a small amount of DiPZn is introduced under fixed flows of DMCd and DETe. Zn composition increases abruptly for further increase of DiPZn flow rate, where growth rate decreases. Growth mechanisms for the above growth conditions were also discussed.     

碲锌镉缓冲层液相外延技术的研究

文章报道了采用液相外延方法，在碲锌镉衬底上进行碲锌镉薄膜缓冲层生长的情况，并且采用X光双晶衍射仪、X光形貌仪、红外傅里叶光谱仪、二次离子质谱仪等手段对碲锌镉薄膜进行了表征，碲锌镉薄膜具有较好地组分及均匀性，晶体结构质量也较好。采用碲锌镉缓冲结构生长了碲镉汞液相外延片，其碲锌镉与碲镉汞薄膜界面附近的杂质得到了有效的控制。     

碲锌镉缓冲层液相外延技术的研究

文章报道了采用液相外延方法，在碲锌镉衬底上进行碲锌镉薄膜缓冲层生长的情况，并且采用X光双晶衍射仪、X光形貌仪、红外傅里叶光谱仪、二次离子质谱仪等手段对碲锌镉薄膜进行了表征，碲锌镉薄膜具有较好地组分及均匀性，晶体结构质量也较好。采用碲锌镉缓冲结构生长了碲镉汞液相外延片，其碲锌镉与碲镉汞薄膜界面附近的杂质得到了有效的控制。     

优质碲锌镉单晶的生长及性能测试

采用垂直布里奇曼法(VB)生长出直径为55mm、低位错密度、结构完好的碲锌隔单晶(Cd0.955Zn0.045Te)。通过位错腐蚀坑密度、傅立叶红外透射光谱、X-Ray形貌、X射线双晶摇摆曲线对碲锌镉晶体的性能进行了研究。     

Cd气氛退火对CdZnTe晶片质量影响

在CdZnTe晶体生长时,有时会产生大颗粒的沉积相,严重的影响了CdZnTe晶片的质量,通过电子探针测试证明其为Cd沉积相.采用Cd气氛退火来消除Cd沉积相,可以改善CdZnTe晶片的质量.实验发现:在较高的温度(600℃)条件下,退火可以有效的消除大颗粒(＞5 (m)的Cd沉积相,改善CdZnTe晶片红外透过率、X射线双晶回摆曲线半峰宽(FWHM)和腐蚀坑密度(EPD).在此条件下对CdZnTe晶片进行退火,有助于提高CdZnTe晶片的性能.     

Growth characteristics of CdZnTe layers grown by metalorganic vapor phase epitaxy using dimethylzinc, dimethylcadmium, diethyltelluride, and dimethyltelluride as precursors

Growth characteristics of (100)-oriented CdZnTe layers grown by atmospheric-pressure metalorganic vapor phase epitaxy have been studied using dimethylzinc (DMZn), dimethylcadmium (DMCd), diethyltelluride (DETe), and dimethyltelluride (DMTe) as precursors. Variations of Zn composition and layer growth rate were examined by changing the DMZn supply ratio, defined as DMZn/(DMCd+DMZn), where the precursors are expressed in appropriate units of flow rate, from 0 (no DMZn) to 1.0 (no DMCd), while keeping the total group II supply rate constant. The growth rate of CdZnTe layers was found to decrease monotonically with increase of the DMZn supply ratio. On the other hand, the Zn composition x of grown layers increased gradually up to x=0.04 with increase of the DMZn supply ratio from 0 to 0.8, beyond which the Zn composition increased abruptly to ZnTe. The abrupt transition of Zn composition was suppressed by increasing the VI/II ratio. The growth mechanism of CdZnTe layers was studied based on the observed growth characteristics of CdTe and ZnTe. A higher desorption rate from the growth surface for Zn species than for Cd species, and a higher rate of CdTe formation than ZnTe formation are believed to cause the observed growth characteristics. CdZnTe layers with high crystal quality were grown in a wide range of Zn compositions. The full-width at half-maximum values for x-ray double-crystal rocking-curve measurements were lower than 320 arc-sec for x<0.3 and x>0.75.     

碲锌镉籽晶定向熔接技术研究

应用CdZnTe晶体作为衬底材料时,其晶向非常关键。CdZnTe晶体籽晶引晶定向生长技术能够有效提高晶体利用率。但是,受碲锌镉晶体生长方法限制,CdZnTe籽晶引晶技术成功率并不高。本文即通过一系列实验研究了籽晶熔接过程升温方式以及籽晶晶向对碲锌镉籽晶熔接成功率的影响,并确定了升温方式是籽晶熔接的关键工艺所在。后续籽晶引晶生长晶向能否持续与籽晶选择晶向有关。通过显著提升初始熔体过热度可以促进<111>籽晶引晶晶向的保持。     

HgCdTe外延用的CdZnTe衬底研制

阐述了ＣｄＺｎＴｅ衬底在红外焦平面阵列探测器研究中的重要性;概括了ＣｄＺｎＴｅ晶体生长的方法、原理和工艺步骤;分析了影响晶体质量（单晶面积、组分及均匀性、结晶完整性、光电特性）的因素,并提出了与质量相关的控制技术;介绍了ＣｄＺｎＴｅ衬底制备过程中,晶片处理的工艺和步骤（晶锭的定向切割、单晶划片、极性鉴别、磨抛、腐蚀）;报道了目前ＣｄＺｎＴｅ晶体的性能水平,晶片处理结果和ＣｄＺｎＴｅ的应用情况。