Formation of thermal donor enhanced by oxygen precipitation in silicon crystal

Kazuhisa Torigoe,Toshiaki Ono

doi:10.1063/1.5140206

Abstract

The formation of thermal donors in silicon is investigated using Czochralski silicon crystals grown with different grown-in defect regions, such as voids and nuclei of oxidation-induced stacking faults. It was found that the formation rate of thermal donors during annealing at 450 °C increases with an increase in the density of oxide precipitates in the regions containing different grown-in defects. The thermodynamic model for the formation of thermal donors shows that the electrically inactive oxygen trimers as nuclei of thermal donors in an as-grown crystal increase with an increase in the density of oxide precipitates, suggesting that the formation of the nuclei is enhanced due to silicon self-interstitials emitted by oxygen precipitations during the crystal growth.

Highlights

Oxygen-related thermal donors (TDs) in silicon have attracted significant attention due to their detrimental effects on the fabrication process of semiconductor devices.1–3 Oxygen atoms are incorporated at a concentration of ∼1018 cm−3 from the melt of silicon in a silica crucible during the Czochralski silicon (Cz-Si) crystal growth and form electrically active species from their aggregates during the cooling process of the crystal growth or subsequent heat treatments
The formation rates are different among the three different defect regions in the as-grown wafers; the formation rates in the regions with oxidation-induced stacking faults (OSFs) nuclei or voids are higher than the region without them
To examine the TD formation kinetics in different grownin defect regions in the silicon crystal, we considered the scitation.org/journal/adv formation model of oxygen clusters by diffusion of interstitial oxygen monomers (O1) and dimers (O2)

Summary

Introduction

Oxygen-related thermal donors (TDs) in silicon have attracted significant attention due to their detrimental effects on the fabrication process of semiconductor devices. Oxygen atoms are incorporated at a concentration of ∼1018 cm−3 from the melt of silicon in a silica crucible during the Czochralski silicon (Cz-Si) crystal growth and form electrically active species from their aggregates during the cooling process of the crystal growth or subsequent heat treatments. Oxygen-related thermal donors (TDs) in silicon have attracted significant attention due to their detrimental effects on the fabrication process of semiconductor devices.. Oxygen atoms are incorporated at a concentration of ∼1018 cm−3 from the melt of silicon in a silica crucible during the Czochralski silicon (Cz-Si) crystal growth and form electrically active species from their aggregates during the cooling process of the crystal growth or subsequent heat treatments. TDs are mainly formed by annealing around 450 ○C and increase with the increase in the isothermal anneal time.. The concentration of TDs reaches a maximum and decays after prolonged annealing above 100 h.1. TDs are readily annihilated at temperatures above 550 ○C due to the small binding energies of one oxygen atom to oxygen clusters, which range from TDs are mainly formed by annealing around 450 ○C and increase with the increase in the isothermal anneal time. Kaiser et al revealed the fourth power dependence of the initial formation rate of TDs on the oxygen concentration, suggesting that TDs are oxygen clusters containing four oxygen atoms. The concentration of TDs reaches a maximum and decays after prolonged annealing above 100 h.1 On the other hand, TDs are readily annihilated at temperatures above 550 ○C due to the small binding energies of one oxygen atom to oxygen clusters, which range from

Results

Discussion

Conclusion