Open AccessA Study on Modified Silicon Surface after CHF 3 /C 2 F 6 Reactive Ion Etching
Author(s) -
Park HyungHo,
Kwon KwangHo,
Lee SangHwan,
Koak ByungHwa,
Nahm Sahn,
Lee HeeTae,
Cho KyoungIk,
Kwon OhJoon,
Kang YoungII
Publication year - 1994
Publication title -
etri journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.295
H-Index - 46
eISSN - 2233-7326
pISSN - 1225-6463
DOI - 10.4218/etrij.94.0194.0014
Subject(s) - x ray photoelectron spectroscopy , reactive ion etching , silicon , fluorine , analytical chemistry (journal) , chemistry , etching (microfabrication) , secondary ion mass spectrometry , fluorocarbon , surface layer , rutherford backscattering spectrometry , materials science , ion , layer (electronics) , chemical engineering , organic chemistry , engineering
The effects of reactive ion etching (RIE) of SiO 2 layer in CHF 3 / C 2 F 6 on the underlying Si surface have been studied by X‐ray photoelectron spectroscopy (XPS), secondary ion mass spectrometer, Rutherford backscattering spectroscopy, and high resolution transmission electron microscopy. We found that two distinguishable modified layers are formed by RIE : (i) a uniform residue surface layer of 4 nm thickness composed entirely of carbon, fluorine, oxygen, and hydrogen with 9 different kinds of chemical bonds and (ii) a contaminated silicon layer of about 50 nm thickness with carbon and fluorine atoms without any observable crystalline defects. To search the removal condition of the silicon surface residue, we monitored the changes of surface compositions for the etched silicon after various post treatments as rapid thermal anneal, O 2 , NF 3 , SF 6 , and Cl 2 plasma treatments. XPS analysis revealed that NF 3 treatment is most effective. With 10 seconds exposure to NF 3 plasma, the fluorocarbon residue film decomposes. The remained fluorine completely disappears after the following wet cleaning.