Oxygen precipitation in Ge-doped Czochralski-silicon at 900 °C investigated by in situ high energy x-ray diffraction

Zhen Li,Johannes Will,Deren Yang

doi:10.1063/5.0027232

Abstract

In this study, we compare the real-time oxygen (O) precipitation kinetics of heavily germanium (Ge)-doped Czochralski-silicon (Cz-Si) at 900 °C—under different pre-annealing conditions—with those of undoped Cz-Si. We follow in situ the evolution of the Bragg intensity in Laue transmission geometry at elevated temperature and identify both diffusion-driven growth and Ostwald ripening of the O precipitates. We build on our past results, where we observed that although Ge-doping at 800 °C facilitates grown-in precipitates, it has no influence on the nucleation rate. Our present results indicate that within a diffusion-driven growth model, Ge-doping influences the nucleation rate at 650 °C and has no impact at 450 °C. These results shed further light on the origin of various thermal historical effects in Cz-Si samples with high levels of Ge doping.

Highlights

During the growth process of Cz-Si, O from the silica crucible is incorporated into Si via the melt, subsequently forming O precipitates
O precipitation in Si has been investigated for decades,7 the lower temperature range from 450 ○C to 650 ○C still has a lot of unanswered questions
With the aim of dissolving the grown-in O precipitates formed during the cooling stage of Cz-Si growth, the specimens were preannealed at 1200 ○C for 3.5 h

Summary

Introduction

During the growth process of Cz-Si, O from the silica crucible is incorporated into Si via the melt, subsequently forming O precipitates. These precipitates have both beneficial (e.g., internal gettering1–4) and detrimental (e.g., recombination centers, dislocation loop, and extrinsic stacking faults4) effects. Considerable research attention has been given to the behavior of O precipitation, especially in respect of Ge-doping. In this context, it is well known that thermal donors are usually produced within the temperature range of 350 ○C–500 ○C.10. It is well known that thermal donors are usually produced within the temperature range of 350 ○C–500 ○C.10 According to previous publications,

Methods

Results

Discussion

Conclusion