Dependence of the Grown-in Defect Distribution on Growth Rates in Czochralski Silicon

Abstract

As-grown defects in 6-inch-diameter Czochralski-silicon crystals grown under different crystal growth rate conditions (0.4, 0.7, 1.1 mm/min) were studied by means of preferential etching and IR light-scattering tomography (LST). Grown-in defect images were classified into four types as follows: (a) flow patterns (wedge-shaped etch pits), (b) IR-defect images observed by LST, (c) ringlike distributed small pits, and (d) large pits. It was found by secondary ion mass spectrometry that IR defects are oxygen precipitates. Large pit defects were identified by transmission electron microscopy as large dislocation loops with a length of about 30 µm. At growth rates from 0.7 mm/min to 1.1 mm/min, flow pattern defects and IR defects coexist inside a ringlike distributed oxidation-induced stacking fault (ring-OSF) region. However, at growth rates less than 0.7 mm/min, large pit defects were observed in the region outside the ring. Characteristic ringlike distributed small pit defects were observed on the outer periphery of the ring region. Flow pattern defects were annihilated during annealing at 1100°C, while IR defects were stable at 1250°C.

The agglomeration dynamics of self-interstitials in growing Czochralski silicon crystals

“…Many studies accomplished before and after the publication of Voronkov's analysis verify its validity [17][18][19][20][21]. The published research on the interaction between vacancies and oxygen in CZ crystals to produce particles of silicon oxides near the vicinity of the boundary between the interstitial dominated regions and the vacancy dominated regions, known as the v/i boundary, further validates Voronkov's theory [18][19][20][22][23][24][25][26][27].…”

Defect dynamics in the presence of oxygen in growing Czochralski silicon crystals

“…The collective dynamics of all reactions including the aggregation events and the transport of all participating species in a growing CZ crystal is termed the CZ defect dynamics. This dynamics in the absence of oxygen has been studied in detail [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34]. These studies, however, do not directly quantify the formation of oxygen clusters in CZ crystals.…”

A Selective Review of the Simulation of the Defect Structure of Dislocation-Free Silicon Single Crystals

“…Stacking faults are formed around the plate of oxygen precipitates [31]. Volume density of precipitates does not change with increasing oxidation time.…”

“…This means that the formation of precipitates takes place during crystal growth. OSF-ring is observed in crystals (diameter 150 mm) grown at 0.7 ... 0.8 mm/min and is absent in crystals grown at 0.4 mm/min and at 1.1 mm/min [31].…”