Discovery of the Czochralski method

he Czochralski method of growing single crystals brought Jan Czochralski his greatest publicity. The method was developed in 1916 and was initially used to measure of crystallization rate of metals. The method was developed as a result of an accident and through Czochralsk’s careful observations. One evening he left aside a crucible with molten tin and returned to writing notes on crystallization study. At some moment, lost in thoughts, instead of dipping his pen in the inkpot, he dipped it in the crucible and withdrew it quickly. He observed then a thin thread of solidified metal hanging at the tip of me nib. The discovery was made! The nib slot, in which crystal lization was initiated, was replaced by a special narrow capillary and in some cases by a seed of the growing crystal. Czochralski checked later that the crystallized wire was a single crystal. The crystals obtained in that way had diameters of about a millimeter and lengths up to 150 mm. Czochralski published a paper on the study of the rate of crystallization of tin, zinc and lead, and the maximum rate of pulling of a crystal was recognized as characteristic of the crystallizing material (Ein neues Yerfahren zur Messung des Kristallisationsgeschwindigkeit der Metalle [A new method for the measurement of crystallization rate of metals]; the paper was received in the editorial office on 19 August 1916

Details of the new method, but without any figure, appeared earlier in another paper published by Czochralski: (Zeitschrift des Vereines Deutscher Ingenieure 61,345-351 (1917)). He is also the author of the first attempt of creating a microscopic theory of recrystallization (Int. Zeitschrift furMetallographie 8,1-43 (1916)).

The application of the Czochralski method exclusively as a tech-nique for obtaining single crystals is due to W. von Wartenberg (Verhandlungen der Deutsche Phys. Gesellschaft 20, 113 (1918)). Thus, the Czochralski method was a method of producing large single crys tals by inserting a small seed crystal into a crucible filled with molten material, then slowly pulling the seed up from the melt with its simultaneous rotation. Later modifications of this method have also been reported. It is interesting to note that in his own investigations Czo chralski obtained single crystals by the Bridgman method. The Czo chralski method was completely forgotten after the World War II. However, increasing demand of materials for semiconductor electronics materials in 1950 led the Americans G.K. Teal and J.B. Little from Bell Telephone Laboratories to rediscover and widely apply this growth meth od, giving it a world-wide fame as the Czochralski method for growing large single crystals on an industrial scale {Growth of germanium single crystals, Phys. Rev. 78, 647 (1950) and Bull. Amer. Phys. Soc. 25, 16 (1950) (Fig. 31 and 32)). At the present time no other crystal growth method can compete with the Czochralski method.