Formation of electronic defects in crystalline silicon during hydrogen plasma treatment

Shota Nunomura,Isao Sakata,Koji Matsubara

doi:10.1063/1.5089202

Shota Nunomura, Isao Sakata + Show 1 more

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https://doi.org/10.1063/1.5089202

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Abstract

Electronic defects in crystalline silicon induced by hydrogen plasma treatments are studied, based on in-situ photocurrent measurements and real-time spectroscopic ellipsometry. The electronic defects are generated by the plasma treatments, and annihilated partially by postannealing. The generation and annihilation of defects strongly depends on both the treatment time and the annealing temperature. A long-time plasma treatment results in the formation of the residual defects in the silicon bulk. The density of these defects is estimated to be of the order of 1013 cm−2. Interestingly, the electronic defects are formed even before a strong modification of the surface structure, i.e., the formation of a nanometer-scale disordered surface layer.

Highlights

The defects are often generated during plasma processing, which is widely used for fabrication of various semiconductor devices.[5,16]
The structures of the disordered surface layer and platelets are analyzed by cross-sectional transmission electron microscopy (TEM)[3,23,24,27] and scanning electron microscopy (SEM)
The electronic states associated with defects are characterized by X-ray photoelectron spectroscopy (XPS) and deep-level transient spectroscopy (DLTS).[3]

Summary

Introduction

The defects are often generated during plasma processing, which is widely used for fabrication of various semiconductor devices.[5,16] In plasma processing, H atoms are generated from H2 molecules or H containing species via dissociation reactions.[19–21]. An increase in the photocurrent reflects the annihilation of defects.[36–39] The mobility is a bulk parameter, which is not influenced by the plasma treatment. In addition to the photocurrent measurement, real-time SE is performed to characterize the disordered surface layer during the plasma treatments.[36,37] This layer is modeled as amorphous Si

Results

Conclusion