单晶硅电火花线切割表面损伤层形成机理

 为了研究单晶硅电火花线切割(WEDM)表面损伤层的损伤形式和形成机理,以电火花线切割加工后的单晶硅表面为研究对象,采用表面形貌观察分析及择优腐蚀方法研究了单晶硅经过电火花线切割后的加工表面.研究结果表明单晶硅经电火花放电加工后表面损伤形式分为4种:热损伤、应力损伤、热与应力综合作用损伤及电解/电化学腐蚀损伤.热损伤使得硅表面形成多晶或非晶硅;应力损伤使硅表面产生裂纹;热与应力综合作用会产生小孔效应,且随着放电功率密度的增加,小孔会明显增多;电解/电化学作用会加快损伤区域及杂质元素富集区域的腐蚀.

Damage Mechanism of Monocrystalline Silicon Cut by WEDM

This paper studies the surface of monocrystalline silicon cut by wire-cut electrical discharge machining(WEDM).The formation mechanism and damage forms of the damaged layer of monocrystalline silicon cut by WEDM are studied by observation and analysis of the surface morphology and anisotropic etching.The results show that there are four kinds of damage forms of the damaged layer: thermal damage,thermal stress damage,combined effects of heat and stress damage,and electrolytic and electrochemical corrosion damage.Thermal damage will produce polysilicon or amorphous silicon on the surface of the silicon;thermal stress damage will make the silicon surface crack;combined effects of heat and stress damage will produce small holes on the suface of the silicon,and the greater the discharge power density is,the more holes there are on the silicon surface;electrolytic and electrochemical reaction will cause accelerated corrosion of the damaged area and the area where contaminants are gathered.