提高（100）晶向磷化铟单晶的成晶率和质量的研究

通过对高压液封直接法单晶生长过程的热传输和影响熔体温度起伏的几个关键因素的分析，研究适全生长（100）晶向磷化铟单晶的热场系统，有效地降低了孪晶产生的几率，重复地生长出了整锭掺硫和掺铁的、直径为50mm和76mm的（100）磷化铟单晶。测试结果表明我们生长（100）磷化铟单晶的热场在生长过程中使晶锭保持较为平坦的固液界面，可稳定地获得具有低的缺陷密度和良好的电学均匀性的高质量磷化铟单晶材料。

Heteroepitaxial Growth and Heterojunction Characteristics of Voids-Free n-3C-SiC on p-Si(100)

Highly oriented voids-free 3C-SiC heteroepitaxial layers are grown on φ50mm Si (100) substrates by low pressure chemical vapor deposition (LPCVD). The initial stage of carbonization and the surface morphology of carbonization layers of Si(100) are studied using reflection high energy electron diffraction (RHEED) and scanning electron microscopy (SEM). It is shown that the optimized carbonization temperature for the growth of voids-free 3S-SiC on Si (100) substrates is 1100 ℃. The electrical properties of SiC layers are characterized using Van der Pauw method. The I-V, C-V, and the temperature dependence of I-V characteristics in n-3C-SiC-p-Si heterojunctions with AuGeNi and Al electrical pads are investigated. It is shown that the maximum reverse breakdown voltage of the n-3C-SiC-p-Si heterojunction diodes reaches to 220V at room temperature. These results indicate that the SiC/Si heterojunction diode can be used to fabricate the wide bandgap emitter SiC/Si heterojunction bipolar transistors (HBT's).

Raman Investigatins of 3C-SiC Films Grown on Si (100) and Sapphire (0001) by LPCVD

The Raman measurements have been performed with the back-scattering geometry on the SiC films grown on Si(100) and sapphire (0001) by LPCVD. Typical TO and LO phonon peaks of 3C-SiC were observed for all the samples grown on Si and apphire substrates, indicating the epilayers are 3C-SiC polytype. Using a free-standing 3C-SiC film removed from Si(100) as a free-stress sample, the stresses of 3C-SiC on Si(100) and sapphire (0001) were estimated according to the shift of TO and LO phonons.

Improved Epitaxy of 3C-SiC Layers on Si(100) by New CVD/LPCVD System

Single crystalline 3C-SiC epitaxial layers are grown on φ50mm Si wafers by a new resistively heated CVD/LPCVD system, using SiH_4, C_2H_4 and H_2 as gas precursors. X-ray diffraction and Raman scattering measurements are used to investigate the crystallinity of the grown films. Electrical properties of the epitaxial 3C-SiC layers with thickness of 1 ～ 3μm are measured by Van der Pauw method. The improved Hall mobility reaches the highest value of 470cm~2/(V·s) at the carrier concentration of 7.7 * 10~(17)cm~(-3).

CeO_2/Si薄膜PL谱的“紫移”

利用双离子束外延技术制备了CeO_2/Si薄膜，椭圆偏振仪测得薄膜厚度为100nm，折射系数约为2.455。实验中发现未经退火处理的CeO_2室温光致发光(PL)谱存在着“紫移”现象，其移动距离约为65nm。利用XRD和XPS对薄膜结构及价态进行分析后表明，PL谱的移动与氧化物中Ce离子价态有关。当Ce离子价态发生Ce~(4+)→Ce~(3+)变化时，其PL谱峰位要从蓝光区向紫光区移动，出现发光峰“紫峰”现象。

Strain Analysis of Cubic AlGaN/GaNGrownon GaAs（100） Substrate by MOVPE

于2010-11-23批量导入

立方相Al_xGa_（1-x）N/GaAs（100）的光致发光研究

于2010-11-23批量导入

立方相GaN/GaAs（100）质量的X射线双晶衍射研究

于2010-11-23批量导入

γ-Al_2O_3/Si(100)薄膜高真空MOCVD异质外延生长

国家计委八五计划,国家计委九五计划

电子束辐照对InP（100）表面硫钝化的增强作用

采用含有过量硫的(NH_4)_2S_x对InP(100)表面进行化学钝化和辉光放电电子束辐照处理,液氮下光致发光强度比未辐射的光致发光强度提高了1.5倍,比未钝化的提高了5倍.利用X射线光电子谱研究了电子辐照对InP表面硫钝化的影响.结果表明,硫钝化InP表面经电子束辐照可以促使S与InP更好的化合.

GaAs（100）的（NH4）2Sx和P2S5/（NH4）2Sx表面钝化

于2010-11-23批量导入

室温下InP（100）表面K诱发催化氮化反应的同步辐射光电子能谱研究

于2010-11-23批量导入

MBE CdTe/GaAs光致发光研究

在10K低温下对分子束外延生长的CdTe（111）B/GaAs（100）和CdTe（211）B/GaAs（211）B外延膜进行了光致发光（PL）测量，得到了PL谱和带边激子辐射的精细结构。