Open volume defects in ultra-thin TiO2 layers embedded in VMCO-like samples studied with positron annihilation spectroscopy

Abstract

Positron annihilation signals from VMCO-like samples grown by atomic layer deposition at different temperatures are utilized for the characterization of differences in open volume defects in TiN/TiO[Formula: see text]/a-Si heterostructures. Doppler and coincidence Doppler mode of positron annihilation spectroscopy combined with a monoenergetic positron beam were used for this study. Differences observed in the Doppler parameters indicate differences in the positron trapping states of the TiO[Formula: see text] epilayers grown at different temperatures. Furthermore, the coincidence-Doppler results show that these differences cannot be due to intermixing of the TiO[Formula: see text] and a-Si layers and formation of thin SiO[Formula: see text] layers at the interface during the growth process. The results indicate that the amount of open volume defects in the TiO[Formula: see text] layer of the VMCO-structure seems to increase with an increase in the growth temperature.

Research progress of coincidence Doppler broadening of positron annihilation measurement technology in materials

“…Beyerlein等 [67] 采用 慢正电子束流CDB技术表征了辐照前后Mg基合 金中的晶体缺陷及化学环境的变化, 发现离子辐照 没有诱导合金中的原子团聚. Liu等 [68] Zhang等 [70] Reiner等 [71] 对Au/Cu双层膜进行不同温度 退火, 研究了膜中的开空间缺陷和元素演化, CDB 谱显示回火过程中伴随着Au薄膜缺陷的回复、 Au与Cu发生合金化, 他们还经过结合理论计算 确定了合金膜成分为Au 0.7 Cu 0.3 . Khanam等 [72] 通 过CDB技术研究了不同温度下原子层沉积生长 的TiN/TiO 2 /a-Si异质结构中开空间缺陷特征的 差异.…”