Growth of homogeneous semiconductor mixed crystals by the traveling liquidus-zone method

Si0.5Ge0.5 bulk single crystals with uniform composition

“…In experiments, sample translation rates were balanced to growth rates and the freezing interface temperature could be fixed. The principle of the TLZ method has been confirmed by the growth of 2 mm diameter crystals [3][4][5][6]. In this study, crystal diameter was increased to 10 mm.…”

“…Origins of polycrystallization were not determined exactly but convection in a liquiduszone might play an important role since more than 25 mm long single crystals were reproducibly grown when crystal diameter was 2 mm [7] in which convection in the liquidus-zone was suppressed. It is considered that convection in a melt homogenizes solute concentration gradient in the melt by stirring and this increases degree of constitutional supercooling [5,[9][10][11]. This situation is schematically illustrated in Fig.…”

“…Si 0.5 Ge 0.5 crystals were grown by the TLZ method [2][3][4][5]. In the TLZ method, a narrow liquidus-zone is formed at a relatively low temperature gradient and the compositional profile almost corresponding to that of liquidus-line is established in the zone.…”

“…Temperature gradients were between 7 and 25 1C/cm. Growth rates were determined depending on temperature gradients in the zone [3][4][5][6] and they were between 0.10 and 0.35 mm/h. Samples were translated at the same rate as the growth rate but in the opposite direction so as to keep the freezing interface temperature constant.…”

“…If high quality Si 0.5 Ge 0.5 substrates are obtained, high speed and low energy consumption CMOS will be realized. We grew compositionally uniform In 1 À x Ga x As crystals by the traveling liquidus-zone (TLZ) method [2][3][4][5]. Then, we applied the TLZ method to the growth of Si 0.5 Ge 0.5 crystals.…”