Dynamics and control of the Czochralski process II. Objectives and control structure design

Abstract A new control system design is proposed for the Czochralski process in order to improve crystal quality, particularly GaAs. An expanded set of formal control objectives are proposed based on a considerations of defect formation, segregation, and the process coupling. A control structure is developed that meets the control objectives and the restrictions posed by the batch related disturbances, system coupling, and the dynamic characteristics of the measurements, outputs, and inputs.

[1]  S. N. Rossolenko,et al.  Analysis of the Dynamics of the Controlled Crystallization Process Using the Czochralski Method , 1986 .

[2]  G. C. Joyce,et al.  The weighing method of automatic Czochralski crystal growth: I. Basic theory , 1977 .

[3]  W. C. Dash.  Silicon Crystals Free of Dislocations , 1958 .

[4]  Michael Athans,et al.  Optimal Control , 1966 .

[5]  A. S. Jordan,et al.  The theoretical and experimental fundamentals of decreasing dislocations in melt grown GaAs and InP , 1986 .

[6]  G. Stein,et al.  The LQG/LTR procedure for multivariable feedback control design , 1987 .

[7]  R. G. Seidensticker,et al.  The basis of automatic diameter control utilizing ``bright ring'' meniscus reflections , 1975 .

[8]  J. C. Brice,et al.  The Czochralski growth of barium strontium niobate crystals , 1971 .

[9]  S. Ostrach,et al.  Convective effects in crystals grown from melt , 1981 .

[10]  U. Gross,et al.  Automatic crystal pulling with optical diameter control using a laser beam , 1972 .

[11]  Torbjörn Carlberg,et al.  Czochralski growth of tin crystals under constant pull rate and IR diameter control , 1986 .

[12]  B. Dam,et al.  The growth spiral morphology on {100} KDP related to impurity effects and step kinetics , 1986 .

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

[14]  G. Stephanopoulos,et al.  Advanced control design considerations for the Czochralski process , 1987 .

[15]  G. C. Joyce,et al.  A technique for experimentally determining the transfer function of a Czochralski pulling process , 1986 .

[16]  G. Stephanopoulos,et al.  Dynamics and control of the Czochralski process: I. Modelling and dynamic characterization , 1987 .

[17]  J. Dikhoff.  Cross-sectional resistivity variations in germanium single crystals , 1960 .

[18]  Milorad P. Dudukovic,et al.  Simulation of jet cooling effects on Czochralski crystal growth , 1986 .

[19]  Jeffrey J. Derby,et al.  Thermal-capillary analysis of Czochralski and liquid encapsulated Czochralski crystal growth: I. Simulation , 1986 .

[20]  Arthur Gelb,et al.  Applied Optimal Estimation , 1974 .

[21]  J. Derby,et al.  Thermal-capillary analysis of Czochralski and liquid encapsulated Czochralski crystal growth. II - Processing strategies , 1986 .

[22]  T. Jones,et al.  Capillary phenomena. Part 11.—Approximate treatment of the shape and properties of fluid interfaces of infinite extent meeting solids in a gravitational field , 1980 .

[23]  P. Van Der Werf,et al.  Diameter control of lec grown GaP crystals , 1974 .

[24]  N. Kobayashi.  Difficulties encountered in Czochralski growth of some oxide single crystals , 1981 .

[25]  Carlos E. Garcia,et al.  Internal model control. A unifying review and some new results , 1982 .

[26]  Manfred Morari,et al.  Design of resilient processing plants. VI: The effect of right-half-plane zeros on dynamic resilience , 1985 .

[27]  D. O'kane,et al.  Infrared TV system of computer controlled Czochralski crystal growth , 1972 .

[28]  T. Fukuda,et al.  In-situ observation of LEC GaAs solid-liquid interface with newly developed X-ray image processing system , 1986 .

[29]  J. Freudenberg,et al.  Right half plane poles and zeros and design tradeoffs in feedback systems , 1985 .