Low Oxygen Content Czochralski Silicon Crystal Growth

Abstract

A low oxygen content silicon crystal ingot with 2.5×1017 to 3.5×1017 atoms·cm-3 was obtained. It was grown by using the Czochralski crystal growth furnace heated with a graphite heater connected to a three phase electrical source, and by controlling the seed and the crucible rotation in conjunction with the fluid rotation caused by the rotating magnetic field of the system. Neither bulk stacking faults after oxidation in wet oxygen at 1100°C for 2 hours, nor oxide precipitates after being annealed in an argon atmosphere at 1000°C for 12 hours, were observed in the crystal.

LEC growth of semi-insulating GaAs crystals in traveling magnetic field generated in a heater–magnet module

“…The path is subdivided in coil segments by contact points for supplying out-of-phase alternating current (AC) in delta or star connection. Note, there are few former sporadic ideas to inject immediate steady [16], rotating [17,18] or traveling magnetic fields [19,20] into a silicon melt by such a heatermagnet combination. However, no detailed experimental and analytical results, especially, of the growth of semiconductor compounds have been reported yet.…”

Travelling magnetic fields applied to bulk crystal growth from the melt: The step from basic research to industrial scale

“…In 1980 Hoshikawa et al [72] and independently Hull [73] reported the first Czochralski silicon crystal growth experiments with such heater-magnet module made of graphite. Rotation rates of 20-30 rpm were observed at the Si melt surface in a 250 mm diameter crucible [72]. Both authors observed an improvement of the oxygen control in the as-grown crystals.…”

Crystal Pulling from the Melt

“…In the late 1970s, workers with large silicon pullers observed systematic anomalies in oxygen content in crystals grown on apparently similar pullers. Specifically it was found that differing oxygen contents could be obtained depending on the sense of the crucible rotation, always with the seed rotating counter to the crucible [114]. Eventually it was discovered that this was due to the rotating magnetic field generated by the three-phase heater elements.…”