Development of High Performance Ohmic Contact Materials for Full Color Light Enitting Devices.

用于全彩发光器件的高性能欧姆接触材料的开发。

基本信息

批准号：
08455145
负责人：
MURAKAMI Masanori
金额：
$ 4.99万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08455145/
关键词：
GaN ZnSe Ohmic Contact Coutact Resistance Schottky Barrier GuN ZnSe 窒化ガリウム

项目摘要

In order to examine the possibility of preparing an non-reacted(non-alloyed)ohmic contacts to p-GaN,the effects of GaN surface treatments and work functions of the contact metals on the electrical properties between the metal contacts and p-GaN were investigated. A contamination layr consisting of GaO_x and adsorbed carbons was found on the GaN substrate grown by metalorganic chemical vapor deposition. The contamination layr was not completely removed by sputtering the GaN surface with Ar and N ions where the ion densities were -10-^2 muA/cm^2. Although the contamination layr was partially removed by immersing in a buffered HF solution, little improvement of the electrical properties of the GaN/metal interfaces was obtained. Most of the vontamination layr was removed by annealing the Ni and Ta contacts at temperatures close to 500ﾟC.These annealed contacts exhibited slightly enhanced current injection from the contact metal to the GaN.The present surface treatment study indicated that … More removal of the contamination layr did not significantly reduce the contact resistance. On the other hand, the resistance decreased exponentially with increasing the metal work functions, where Pt, Ni, Pd, Au, Cu, Ti, Al, Ta, and Ni/Au were deposited on the GaN.This result suggests that the Schottky barrier height at the p-GaN/metal interface might not be pinned at the GaN surface. The present study concluded that a contact metal with a large work function is desirable for non-reacted ohmic contacts to p-GaN.However, these contacts did not provide the law contact resistance required for blue laser diodes.In addition, Schottky barrier heights(SBH's)of a variety of metals(In, Cd, Nb, Ti, W,Cu, Ag, Au, Ni, Pt, and Se)contacting to p-ZnSe grown by a molecular beam epitaxy method were measured by an intenal photoemission, capacitance-voltage(C-V)、and/or current density-voltage(J-V)method. The internal photoemission method could not measure accurately the SBH's of these metals due to a strong interference of the monochromatic incident light in the p-ZnSe epilayr. The C-V method measured the SBH value of 1.23 eV for the Au contact and 1.13 eV for the Ni contact, but did not measure the SBH's of other metals due to strong hysteresis of the C-V curves. The SBH's of these metals were successfully measured by the J-V method to be 1.2(]SY.+-。[)0.1 eV.The present experiment showed that the SBH values were independent of the work functions of the contact metals, indicating that the Fermi-level could be pinned at the p-ZnSe/metal interface. In addition, turn-on voltages conventionally used to evaluate the electrical properties of the contact metals were found to be very sensitive to the SBH values. Less

为了检查与p-gan制备非反应（非合成）欧姆接触的可能性，研究了GAN表面处理的影响以及接触金属对金属接触和P-GAN之间电气性能的作用。在金属有机化学蒸气沉积生长的GAN底物上发现了由GAO_X和吸附碳组成的污染Layr。通过用Ar和N离子溅射离子密度为-10-^2 MUA/CM^2的Ar和N离子，并未完全去除污染Layr。尽管通过浸入缓冲的HF溶液中部分去除污染Layr，但几乎没有改善GAN/金属界面的电性能。通过在接近500°C的温度下退出Ni和TA触点，消除了大部分远程征态Layr。这些接触的接触略微增强了从接触金属到GAN的电流注射略有增强。目前的表面处理研究表明，……污染Layr的更多去除并未显着降低接触电阻。另一方面，随着金属工作功能的增加，电阻呈指数降低，其中PT，Ni，Pd，Au，Cu，Cu，Ti，Ti，Al，Ta和Ni/Au被沉积在GAN上。这表明P-GAN/金属界面的Schottky屏障高度可能不会在gan表面固定在P-GAN/金属界面上。本研究得出的结论是，具有较大工作功能的接触金属对于与p-gan的无抗欧姆接触是可取的。通过分子束外延法生长的P-ZNSE通过强度光发射，电容 - 电压（C-V）和/或电流密度 - 电压（J-V）方法测量。由于P-ZNSE Epilayr中单色入射光的强烈干扰，因此内部光发射方法无法准确测量这些金属的SBH。 C-V方法测量了AU接触的SBH值为1.23 eV，而NI接触的SBH值为1.13 eV，但由于C-V曲线的较强滞后，未测量其他金属的SBH。这些金属的SBH通过J-V方法成功测量为1.2（]SY。+ - 。[）0.1 eV。目前的实验表明，SBH值与接触金属的工作函数无关，表明Fermi-Level可以固定在P-ZNSE/金属界面上。此外，发现传统用于评估接触金属的电特性的转交压对SBH值非常敏感。较少的