Oxygen distribution in silicon-on-insulator layers obtained by zone melting recrystallization

Abstract

The oxygen content in zone melting recrystallization silicon-on-insulator (ZMR SOI) layers with thicknesses ranging between 0.5 and 25 μm obtained with a movable lampheater is studied. Secondary-ion-mass spectrometry profiling as well as numerical calculations are presented. The simulations are based on oxygen redistribution during cooling down. In the model it is assumed that the interface reaction is fast enough to be not the rate-limiting step in the redistribution process. Consequently, the oxygen transport was considered to be entirely diffusion limited. Good agreement was found between the measurements and calculated values. The profiles show a maximum at the center of the layer and symmetrically depleted regions in the top and bottom of the silicon film. It has been generally accepted that ZMR SOI layers have a high oxygen concentration corresponding to the saturation level at melting point. In the present study, however, we show that in the 0.5-μm layers the oxygen concentration is as low as 1×1017(O atoms)/cm3.

Thermodynamics and phase stability in the Si–O system

“…The values of [147] are not corresponding to the data chosen for the present assessment, the values of [148] are widely scattered and [130] do not give the source of their data. Only one value is reported by [149] and [150] near the melting point. The value of [149] was adopted by [3], however, this is no experimental data but an assessed value.…”

“…If they are determined experimentally, the value is very dependent on the experimental method, published values ranging from 0.25 to 2.5. An instructive review on the intricacies of its determination in the crystal growth process and the difference between the Ôequilibrium' and the [149] 1688:05 < T < 1688:11 Assessment 1990 [150] Ramped down from 1573 ZMR SOI, SIMS 1998 [170] In CZ crystal FTIR, SIMS a VFA: ¼ vacuum fusion analysis, IR: ¼ infrared spectroscopy, XRD: ¼ X-ray diffractometry, AA: ¼ activation analysis, TEM: ¼ transmission electron microscopy, FTIR: ¼ fourier transform infrared spectroscopy, SIMS: ¼ secondary ion mass spectroscopy, ZMR SOI: ¼ zone melting recrystallization silicon-on-insulator. [156] 1723-1820 Ampoule, Q-IGFA 1993 [185] 1720-1815 SIMS, Q-GFA 1994 [186] 1693-1823 Q-IGFA, IR 1994 [158] T m Q-M, FTIR 1994 [187] 1723-1823 EMF, Q-VFA 1995 [188] T m Q-M, FTIR 1997 [151] 1703-1743 SIMS, Q-GFA 1997 [152] 1703-1743 SIMS, Q-GFA 1997 [159] 1687-1833 EMF a Q-FZ: ¼ quenched float zone, Q-M: ¼ quenched melt, IR: ¼ infrared spectroscopy, VFA: ¼ vacuum fusion analysis, AA: ¼ activation analysis, FTIR: ¼ fourier transform infrared spectroscopy, SIMS: ¼ secondary ion mass spectroscopy, (I)GFA: ¼ (inert) gas fusion analysis, EMF: ¼ electromotive force.…”