Study Of The Process Of Copper Plating On Silicon Surface Based Upon Self-assembly Technology

Metallization of silicon could further expand its application fields,which is widely used in various technological fields such as electronic computer,electric control,communication engineering,electrical accessory and so on.Metallization of silicon surface can make them have the advantage of both electrical conductivity and magnetic permeability.The pretreatment of silicon plays an important role for copper plating.However,the traditional process is not only complex,but also damages the material surface.Therefore,a non-damaging and simple operation method is necessary.In this paper,plasma technology and hydrophilic agent were used to conduct pretreatment.(3-aminopropyl)triethoxysilane(APTES)was used to fabricate self-assembled film on the pretreated silicon surface,then APTES film modified substrate was treated by electroless copper plating and copper electroplating.With the help of energy dispersive X-ray detector and scanning electron microscope,the element contents and morphologies of copper film were characterized,The experimental conclusion is as follows:(1)The optimal conditions preparing self-assembled film are APTES concentration of 3mM,H2O/CH3CH2 OH of 10/90,hydrolysis 24 h under 35? and curing time of 50 min under100 ? in the oven.The porous morphology and hydrophilic surface were abtained in these experiment condition,which could lay a foundation for copper plating.(2)By orthogonal test and SEM,the electroless copper plating on the APTES self-assembled film modified silicon surface was studied.The dense and uniform coating on silicon surface and good adhesion property between silicon and copper plating were obtained under the condition of 30 min electroless copperplating time,temperature of 55°C and pH of12.6.(3)The condition of electrical copper was concentration of CuSO4·5H2O of 133 g/L,H2SO4 of 6.6 ml/L,NaCl of 53.3 mg/L.By single factor test and cyclic voltammetry,the best copper film is obtained under the condition of 600 s copper plating time,current density of1.56 A/dm2.The copper film with metallic luster is dense and homogeneous.The excellent adhesion property of copper layer is obtained,which is essentially based on the formation of coordinate bond between –NH2 of APTES and copper.The method of copper plating on silicon is un-damaging,simple and efficient.