ON THE MECHANISM OF CHEMICALLY ETCHING GERMANIUM AND SILICON
ON THE MECHANISM OF CHEMICALLY ETCHING GERMANIUM AND SILICON
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DOI：
10.1149/1.2427519
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发表时间：
1960-01-01
影响因子：
3.9
通讯作者：
TURNER, DR
中科院分区：
文献类型：
--
作者：
TURNER, DR
The electrode potential of germanium or silicon in a chemical etching solution is a function of solution pH, rate of etching, physical condition of the surface, conductivity type, and resistivity. The results suggest that excess holes and electrons are produced at the surface of the semiconductor during chemical etching. Holes are injected at cathode sites, but only a portion of these holes are consumed at anode sites since the anode reaction involves current multiplication.Semiconductors such as Ge or Si are chemically etched in aqueous solutions containing an oxidizing agent such as nitric acid and an anion such as F-which is capable of forming water-soluble complexes with the semiconductor. The etching process is actually electrochemical in its action, that is, there are anode and cathode sites on the surface of the semiconductor with local cell currents flowing between them. Semiconductor material goes into solution at the anodic sites while the oxidizing agent is reduced at the cathodic areas. The rate of chemical etching is determined by the magnitude of the corrosion current. If the etching process is nonpreferential and material is removed uniformly, any given area on the surface of the semiconductor must continually alternate between being anode and cathode. When one spot is anodic much more than it is cathodic, an etch pit will form at that point. Experience has shown that this is most likely to occur at grain boundaries and dislocations at the surface of the single crystal. Conversely, hillocks are formed on areas that are cathodic more than they are anodic.
