物理化学学报 >> 2009, Vol. 25 >> Issue (08): 1671-1677.doi: 10.3866/PKU.WHXB20090810

研究论文 上一篇    下一篇

不同类型GaAs上应用约束刻蚀剂层技术进行电化学微加工

汤儆, 王文华, 庄金亮, 崔晨   

  1. 厦门大学化学化工学院化学系, 福建 厦门 361005
  • 收稿日期:2009-01-08 修回日期:2009-05-16 发布日期:2009-07-16
  • 通讯作者: 汤儆 E-mail:jingtang@xmu.edu.cn

Electrochemical Micromachining on Different Types of GaAs by Confined Etchant Layer Technique

TANG Jing, WANG Wen-Hua, ZHUANG Jin-Liang, CUI Chen   

  1. Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian Province, P. R. China
  • Received:2009-01-08 Revised:2009-05-16 Published:2009-07-16
  • Contact: TANG Jing E-mail:jingtang@xmu.edu.cn

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摘要：

应用约束刻蚀剂层技术(CELT)对GaAs进行电化学微加工. 研究了刻蚀溶液体系中各组成的浓度比例、GaAs类型、掺杂以及阳极腐蚀过程对GaAs刻蚀加工过程的影响. 循环伏安实验表明, Br-可以通过电化学反应生成Br2作为刻蚀剂, L-胱氨酸可作为有效的捕捉剂. CELT中刻蚀剂层被紧紧束缚于模板表面, 模板和工件之间的距离小于刻蚀剂层的厚度时, 刻蚀剂可以对GaAs进行加工. 利用表面具有微凸半球阵列的导电模板, 可以在不同类型GaAs上加工得到微孔阵列. 实验结果表明: 在相同刻蚀条件下, GaAs的加工分辨率与刻蚀体系中各组分的浓度比例有关, 刻蚀结构的尺寸随着刻蚀剂与捕捉剂浓度比的增加而增大; 在加工过程中, p-GaAs相对于n-GaAs和无掺杂GaAs受到阳极氧化过程的影响较为显著, p-GaAs表面易生成氧化物层, 影响电化学微加工过程. X射线光电子能谱(XPS)和极化曲线实验也证明了这一点.

关键词: 阳极溶解, 砷化镓, 约束刻蚀剂层技术, 刻蚀剂, 捕捉剂

Abstract:

The confined etchant layer technique (CELT) was applied to electrochemical micromachining on different types of GaAs (p-type, n-type, undoped). Cyclic voltammetry curves showed that the etchant bromine was generated on the mold and L-cystine was thus used as an efficient scavenger to react quickly with the etchant. Therefore, the etchant was confined very close to the surface of the mold and it etched the workpiece of GaAs when the distance between the mold and workpiece was less than the thickness of the confined etchant layer. An array of concave microstructures was fabricated on different types of GaAs by CELT using a mold with an array of convex hemispheres. Several factors including the concentration ratio between the etchant and the scavenger, types of GaAs, and anodic oxidation during the process of CELT were studied. Experimental results showed that the resolution of electrochemical micromachining increased when the thickness of the confined etchant layer decreased. During the microfabrication process, anodic dissolution affected the electrochemical micromachining of p-type GaAs much more than that of the other two types of GaAs. The oxide layer on p-GaAs had a strong influence on electrochemical micromachining. X-ray photoelectron spectroscopy (XPS) and polarization curves also proved the existence of the oxide layer on p-GaAs.

Key words: Anodic dissolution, GaAs, Confined etchant layer technique, Etchant, Scavenger