Plasma Immersion Ion Implantation System Development And Its Associated Physics

Plasma immersion ion implantation(Pâ…¢) circumvents the line-of-sight restriction inherent in conventional ion implantation.Pâ…¢is an excellent alternative to conventional ion implantation in a number of areas pertaining to the surface treatment of metal and polymer and the manufactory of semiconductor device,because of its high efficiency,compatible with plasma processing and good ability to handle the complex workpiece of three dimensions.We setup one Pâ…¢system for semiconductor application,consisting of the inductively coupled plasma,vacuum chamber and the impulse power supply.A humped spiral antenna of top inductively coupled plasma with variable gap has been developed.Compared with planar spiral antennae,the performance of humped spiral antennae has been investigated in the calculated electromagnetic configurations and experimental results.It is found that the humped antenna has the improved uniformity of plasma density in the radial direction and the decreased electron temperature in the top inductively coupled plasma.By experimentally and theoretically analyzing,the plasma performance in the case of humped antennae is considered to be the combined results of the uniform electromagnetic configurations and the depressed capacitively coupling effect.The alternative plasma source has been applied in Pâ…¢,which satisfies the demand of high density,large volume and good uniformity.The surface wave plasma excited by an annular slot antenna is described.The experimental results showed that the uniformity of plasma density in the radial direction has been improved.The surface plasmon polaritons (SPPs) generated by surface wave plasma on the interface between plasma and dielectric have been investigated.The wavelength of surface SPPs at the dielectric-plasma interface as the functions of incident wave frequency and plasma density has been calculated.Some interesting experiment phenomena of light patterns that appear in microwave plasma have been observed.The comparison of the experiment results with the calculating results has been carried out.By experimentally and theoretically analyzing,the phenomena are considered to be caused by the surface wave of SPPs at the interface between Pyrex wall and plasma.The influence of negative high voltage on plasma density in plasma immersion ion implantation has been investigated.It is found that the bulk plasma density have an increasing tendency toward the increasing repetitive frequency and the increasing pulse width of high voltage,while insensitive to the increasing high voltage.By experimentally and theoretically analyzing,the density performance in the case of high voltage is considered to be the combined results of the changes in ionization cross section and second electron yield coefficient.The investigation of semiconductor material processed in our Pâ…¢system has been carried out.The blue-shift phenomena of the luminescent porous silicon after Pâ…¢processing have been observed and interpreted by the new phase of Si-N_xO_y.The decreasing in electron concentration and electron mobility of ZnO film after Pâ…¢provides the useful information for the fabrication of p-type ZnO.