• Electrical & Electronic Materials
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• v.7 no.4
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• pp.294-299
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• 1994

CHF$_{3}$/CH$_{4}$Ar 플라즈마에 의해 형성된 산화막 식각 잔류물의 화학구조와 이 잔류물의 제거를 위한 세정방법을 x-ray photoelectron spectroscopy를 이용하여 조사하였다. 잔류무르이 구조는 CF$_{x}$-polymer와 Si-C, Si-O 결합으로 이루어진 SiO$_{y}$ C$_{z}$ 이었다. CF$_{4}$O$_{2}$ 플라즈마에 의한 silicon light etch는 산화막 식각 잔류물인 SiO$_{y}$ C$_{z}$ 층과 손상된 실리콘 표면을 제거하엿으며 NH$_{4}$OH-H$_{2}$O$_{2}$과 HF용액으로 완전히 제거되는 CF$_{x}$-polymer/SiO$_{x}$층을 남겼다. 100.angs.정도의 silicon light etch는 minority carrier life time과 thermal wave signal값을 초기 웨이퍼 수준까지 회복시켰으며 접합누설 전류도 거의 습식 식각 공정수준까지 감소시켰다.

• ETRI Journal
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• v.16 no.1
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• pp.45-57
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• 1994

The effects of reactive ion etching (RIE) of $SiO_2$ layer in $CHF_3/C_2F_6$ 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.