This project studies the impact on ‹110› dislocation-free monocrystal grown by Czochralski method (hereinafter referred to as CZ) through puller's heat zone system and pulling process. Adjusting heat system appropriately, increasing pulling speed sharply, controlling the diameter and length in neck growth, controlling the speed in crown growth, increasing the length and diameter of tail, all of which are key elements to guarantee the success of ‹110› dislocation-free monocrystal pulling. The ‹110› dislocation-free monocrystal we developed under this project can be applied to optoelectronic devices for both semiconductor and solar industry. According to the verifications of the customer, the solar cell manufactured by ‹110› silicon monocrystal has unique features of ultra-thin and high efficiency. Furthermore, it can solve the problem caused by sheltering issue. Compared to traditional solar cell, silicon usage is 3 times less. As a result, it reduces the material cost dramatically.

In this paper, the radial resistivity variation (RRV) of the gas doped floating-zone (GDFZ) silicon has been studied through of three factors that are the lower shaft rotation speed, the timeratio of the lower shaft clockwise(CW) rotation speed and the counterclockwise (CCW) rotation speed, and the eccentricity between the upper shaft and the lower shaft in the horizontal direction. Test results show that the lower shaft speed has greatly influenced the RRV of GDFZ silicon, and with the increase of the shaft speed, radial deviation of the resistivity decreases first and then increases. As the timeratio between the lower shaft of CW&CCW rotation speed increases, the single crystal radial resistivity distribution is improved. As reversible angle of CW&CCW further increasing, radial deviation of the resistivity distribution rises again. With the increases in eccentricity ing, resistivity variation between the edge and the center decreases, thus radial resistivity inhomogeneity of single crystal significantly is also reduced. Based on the above study, further optimization of process, reasonable regulation and control of shaft speed, reversible angle, eccentricity and other parameters selected during GDFZ process can be obtained, which would obtain good radial resistivity uniformity to meet the requirements of the semiconductor devices.

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