Allan I. Bennett

Web Growth of Semiconductors

A novel process for growth of diamond‐lattice semiconductors is described, and a model is proposed for the growth mechanism. For germanium the process yields extended thin flat sheets, typically 1 cm wide and 0.1 mm thick, of good crystalline quality and relatively flat {111} surfaces. The sheet, or web, freezes from a liquid film drawn up by surface tension between two coplanar dendrites which originate from a single seed and are grown from the melt simultaneously with the sheet. Resistivity throughout the sheet is quite uniform. Etching of germanium webs shows them to be essentially dislocation‐free and does not reveal any microsegregation of impurities. Silicon and indium antimonide have also been grown in this manner.The proposed model postulates that although the dendrites at either side of the web grow beneath the melt surface in usual dendritic fashion, the faces of the web itself normally have no extension below the melt surface. The exterior contact angle between the solid and liquid surfaces is ...

Growth of Atomically Flat Surfaces on Germanium Dendrites

This note presents a theory of the formation of extended flat surfaces on germanium dendrites. It is suggested that part of the liquid‐solid interface is a supercooled {111} surface, on which new atomic planes are occasionally nucleated. Thermal limitations on the nucleation and propagation of these monolayers are discussed. When such a growing layer reaches the melt surface it creates a step on the solid. It is proposed that the meniscus momentarily sticks to the corner of this step. Subsequent planes nucleated during this sticking period result in a step several atomic layers high, in accord with experiment. Elementary estimates of corner energy and amount of meniscus sticking yield results consistent with experiment.