论文信息 - A technique for experimentally determining the transfer function of a Czochralski pulling process

A technique for experimentally determining the transfer function of a Czochralski pulling process

Abstract A technique has been developed to determine the dynamic response of a growing crystal to changes in heater power. This is done by measuring the transfer function (TF) between heater power as “input” and rate of change of crystal weight as “output”. A minicomputer was used to modulate the heater power and monitor the system response. A parameter estimation technique was utilised to express the TF as the ratio of two polynomials from which the frequency response was obtained. The results of a study of the growth of germanium in a resistively heated puller are presented.

[1] V. A. Tatarchenko. Capillary shaping in crystal growth from melts: I. Theory , 1977 .

[2] D. Hurle. Control of diameter in Czochralski and related crystal growth techniques , 1977 .

[3] C. Sanathanan,et al. Transfer function synthesis as a ratio of two complex polynomials , 1963 .

[4] G. C. Joyce,et al. The weighing method of automatic Czochralski crystal growth: II. Control equipment , 1977 .

[5] T. Surek,et al. Theory of shape stability in crystal growth from the melt , 1976 .

[6] A. B. Crowley,et al. Mathematical Modelling of Heat Flow in Czochralski Crystal Pulling , 1983 .

[7] Benjamin C. Kuo,et al. Digital Control Systems , 1977 .

[8] E. Sachs,et al. Dynamics and control of meniscus height in ribbon growth by the EFG method , 1980 .