Hot Cathode Dc Pcvd Method Of Diamond Film Growth Characteristics And Nitrogen Doping Research

Diamond is a new type functional material. Due to its combinedexcellent mechanical, electrical, thermal and optical properties, diamondhas wide and potential applications in optoelectronics and mechanics.Therefore, widen researches in the growth of diamond films are made andthe artificial synthetic mechanism of diamond films are well known.However, the quality of diamond still needs to be improved. So the urgentissues we must face are to know the synthetic mechanism of diamonddeeply, improving the experiment conditions to make diamond films withhigh guality extend its applications.The growth and doping characteristics of diamond films on P type（111） single-crystal silicon substrate are studied by method of DC-PCVD inthis paper;the morphology the structure orientation and its conductiutycharacteristics of diamond films on different experimental conditions areanalyzed systematically by SEM, Raman, XRD and Hall measurement.Theresults gotten are as follows. （1）In CH₄/H₂atmosphere, with the increasing pressure, the quality ofthe diamond film changes from high to low and grows with the increase ofpressure. Moreover, it is not good for diamond to crystallize in lowtemperature. Besides, the defects at more and high temperature makediamond grain coarsening. The influence of CH4are mainly as follows:firstly, increasing CH₄can increase the average temperature of electrons;secondly, increasing C₂makes growing rate accelerate but lowers thequality of film and decreases the size of grain. Furthermore, withmicrometer film growing, nano-diamond film can be produced by loweringsubstrate temperature and pressure in reaction room.（2）In CH₄/H₂atmosphere, diamond film with nitrogen doping isprepared, which is mixed in the melamine saturated solution steam ofmethanol by hydrogen blister. The research shows that a little nitrogenmixed makes crystallite size reduce, non-diamond carbon phase in the filmincrease and resistivity decrease.（3）In CH₄/H₂/Ar atmosphere, nano-diamond film with nitrogen atoms from C₃H₆N₆was prepared by changing the flow rate of Ar and H₂. Theresult shows that as the flow rate increases, the grain in film is fine;moreover, boundaries, dislocations and defects increase. What’s more, theamount of non-diamond increases gradually and resistivity is lower to10^-2·cm.