Effect of high-temperature annealing on the dissolution of the D-defects in n-type Czochralski silicon

Abstract

The effect of high-temperature annealing on the dissolution of crystal grown-in defects referred to as D-defects in n-type Czochralski silicon under various annealing conditions was studied. Annealing at 1200 °C for 1 h in either oxygen or nitrogen ambient causes the dissolution of the D-defects while in contrast no effect of a high-temperature annealing in hydrogen ambient on the D-defects was observed. Based upon the present analysis, D-defect dissolution during oxygen and nitrogen annealing could be attributed to vacancy undersaturation resulting from silicon interstitial injection from the silicon surface. Annealing in hydrogen ambient is hypothesized to cause vacancies at the surface sites to migrate into the silicon lattice via a Schottky defect formation mechanism.

Physical Model of Paths of Microdefects Nucleation in Dislocation-Free Single Crystals Float-Zone Silicon

“…In this area only interstitial D-microdefects is observed. Furthermore, temperature of formation of interstitial D-microdefects T = 1150°C well correlates with temperature of a dissociation D-microdefects [32,65]. However in Refs.…”

“…However in Refs. [32,65] were investigated CZ-Si in which, according to [17], D-microdefects had a vacancy nature. Therefore, if not to use a disputable nomenclature about "D-microdefects" we may say that in Refs.…”

“…Therefore, if not to use a disputable nomenclature about "D-microdefects" we may say that in Refs. [32,65] temperature of formation of interstitial D-microdefects was determined. This position is well correlates with results of our quenching experiments.…”

Phosphorus Concentration Limitation in Czochralski Silicon Crystals

“…The wafers were first etched with Secco etch 9 without agitation to reveal D defects or flow pattern defects (FPD). 10,11 Each wafer was weighted before and after the Secco etch for removal calculations. The acid temperature was kept less than 18ЊC to remove about 3.8 to 4.2 m thick of silicon from each side.…”

Determination of silicon evaporation rate at 1200 °C in hydrogen

“…Thermal annealing in hydrogen at high temperature has been found to bestow on the wafers very promising properties, 4 such as improved breakdown voltage of the thermal oxide, etc., and stimulated a wide variety of interests. [5][6][7][8] This technique might, however, encounter a serious problem if the crystal is etched away fiercely by hydrogen. Suppose an evaporation rate, for example, faster than the dissolution of oxygen precipitates which is inevitably present in all Czochralski ͑CZ͒ silicon crystals.…”