Comparative study of erbium disilicide thin films grown in situ under ultrahigh vacuum or ex situ with a capping layer

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• 作者：N. Reckinger^a ; ^{nicolas.reckinger@uclouvain.be} ; C.A. Du牛u^a ; X. Tang^a ; E. Dubois^b ; D.A. Yarekha^b ; S. Godey^b ; L. Nougaret^c ; A. 艁aszcz^d ; J. Ratajczak^d ; J.-P. Raskin^a
• 关键词：Erbium disilicide ; Thin film ; Structural characterization ; Schottky barrier height ; Ultrahigh vacuum ; Capping layer
• 刊名：Thin Solid Films
• 出版年：2012
• 期刊代码：78_00406090
• 类别：ph
• 出版时间：30 April, 2012
• 卷：520
• 期：13
• 页码：4501-4505
• 文件大小：912 K

摘要

Erbium disilicide (ErSi_2-x) thin films grown by two different techniques are compared using a variety of characterization techniques, both electrical and physical. The first technique involves Er deposition and annealing under ultrahigh vacuum and the second one focuses on Ti/Er/Si(100) stacks evaporated under high vacuum and heated ex situ by rapid thermal annealing. Crystalline phase identification by X-ray diffraction reveals the formation of ErSi_2-x for all the studied samples. Cross-sectional transmission electron microscopy shows that the Ti cap transforms into Ti-Si compounds. The efficient stripping of the capping layer is also demonstrated. Atomic force microscopy evidences the formation of inverted pyramidal defects in both cases, with some improvement for the Ti-capped samples. X-ray photoelectron spectroscopy depth profiles show that the ErSi_2-x films and the ErSi_2-x/Si interfaces are oxygen-free. The extracted Schottky barrier height of ErSi_2-x/n-Si contacts lies around 0.3 eV notwithstanding the annealing temperature or the growth technique. It thus demonstrates a route to form ErSi_2-x thin films that advantageously compares with reference ultrahigh vacuum samples with less stringent fabrication conditions.