• 반도체디스플레이기술학회지
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• 제16권1호
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• pp.22-28
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• 2017

The result of stripping process for the removal of the post etch/ash Photoresist (PR) residue on an aluminum patterned wafer by using supercritical $CO_2$ ($sc-CO_2$) mixture, was investigated by scanning of electron microscope (SEM) inspection of wafer, measuring the cloud points and visual observation of the state of $sc-CO_2$ mixtures. It was found that $sc-CO_2$ mixtures were made by mixing additives and $sc-CO_2$ should form homogeneous and transparent phase (HTP) in order to effectively and uniformly remove the post etch/ash PR residue on the aluminum patterned wafer using them. The additives were formulated by mixing and co-solvents like an amine compound and fluorosurfactants used as HTP agents, and the PR residue on the wafer were able to be rapidly and effectively removed using the $sc-CO_2$ mixture of HTP. The five kinds of additives were formulated by the recipe of mixing co-solvents and surfactants, which were able to remove PR residue on the wafer by mixing with $sc-CO_2$ at the stripping temperature range from 40 to $80^{\circ}C$. The five kinds of $sc-CO_2$ mixtures which were named as PR removers were made, which were able to form HTP within the above described stripping temperature. The cloud points of $sc-CO_2$ mixtures were measured to find correlation between them and HTP.

• 반도체디스플레이기술학회지
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• 제16권2호
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• pp.55-60
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• 2017

The supercritical $CO_2$ (sc-$CO_2$) mixture and the sc-$CO_2$-based Photoresist(PR) stripping(SCPS) process were applied to the removal of the post etch/ash PR residue on aluminum patterned wafers and the results were observed by scanning of electron microscope(SEM). In the case of MDII wafers, the carbonized PR was able to be effectively removed without pre-stripping by oxygen plasma ashing by using sc-$CO_2$ mixture containing the optimum formulated additives at the proper pressure and temperature, and the same result was also able to be obtained in the case of HDII wafer. It was found that the efficiency of SCPS of ion implanted wafer improved as the temperature of SCPS was high, so a very large amount of MEA in the sc-$CO_2$ mixture could be reduced if the temperature could be increased at condition that a process permits, and the ion implanted photoresist(IIP) on the wafer was able to be removed completely without pre-treatment of plasma ashing by using the only 1 step SCPS process. By using SCPS process, PR polymers formed on sidewalls of metal conductive layers such as aluminum films, titanium and titanium nitride films by dry etching and ashing processes were removed effectively with the minimization of the corrosion of the metal conductive layers.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.501-504
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• 1999

In the shallow trench isolation(STI) chemical mechanical polishing(CMP) process, the key issues are the optimized thickness control within- wafer-non-uniformity, and the possible defects such as nitride residue and pad oxide damage. These defects after STI CMP process were discussed to accomplish its optimum process condition. To understand its optimum process condition, overall STI related processes including reverse moat etch, trench etch, STI filling and STI CMP were discussed. It is represented that the nitride residue can be occurred in the condition of high post CMP thickness and low trench depth. In addition there are remaining oxide on the moat surface after reverse moat etch. It means that reverse moat etching process can be the main source of nitride residue. Pad oxide damage can be caused by over-polishing and high trench depth.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1993년도 춘계학술발표회
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• pp.45-45
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• 1993

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 추계종합학술대회
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• pp.747-750
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• 2007

본 연구는 부식을 방지하기 위해서는 metal line식각 후 염소 잔유물 과 plasma charge up을 식각 조건, PR strip조건 및 후속 세정 조건을 최적화함으로써 제거해야 한다고 제안 하였다. Metal line에 다량 분포하는 charge up은 후속 세정의 적정 PH와 만났을 때, 하부 tungsten plug의 부식을 유발 하게 된다. Metal line식각 및 PR strip후 세정에 있어 약액의 종류는 부식에 결정적인 영향을 미친다. Galvanic corrosion을 최소화하기 위한 적정 PH, metal attack을 최소화 할 수 있는 chemistry선택, 높은 식각 부산물 제거 효율의 약액, 최적의 $H_2O$처리 조건 등이 metal부식방지에 있어 결정적인 요소임을 확인하였다.

• Korean Chemical Engineering Research
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• 제59권4호
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• pp.632-638
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• 2021

반도체 공정에서 구리 배선 공정의 도입에 따라 플라즈마 식각에 의해 배선의 형성과정에서 구리 산화물, 불화물 및 불화탄소 등을 포함한 복합 잔류물을 형성하게 된다. 본 연구에서는 아민기(-NH₂)와 카르복실기(-COOH)를 갖는 성분으로 세정액을 제조하여 구리 배선 공정에서의 식각 잔류물 제거 특성을 분석하였다. 아민기를 포함한 세정액은 질소에 치환된 성분 및 탄소결합의 길이에 따라 세정효과에 차이를 보이며, 세정액의 pH가 증가함에 따라 구리 산화물의 식각 속도가 증가하는 경향성을 보였다. 아민기의 활성은 염기성 영역에서, 카르복실기의 활성은 산성 영역에서 이루어지며, 각각의 영역에서 구리 또는 구리 산화물과의 complex 형성을 통하여 세정공정이 진행되었다.

• 한국표면공학회지
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• 제32권2호
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• pp.93-99
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• 1999

Surface polymer layer formed on the silicon wafer during the oxide overetching using $C_4F_8$/ helicon wave plasmas and their characteristics were investigated using spectroscopic elipsometry, X-ray photoelectron spectroscopy, and secondary ion mass spectrometry. Overetch percentage and dc-self bias voltage were varied to investigate the effects on the characteristics of the polymers remaining on the overetched silicon surface. The increase of bias voltage from -80 volts to -120 volts increased the C/F ratio and carbon bondings such as C-C, $C-CF_x$/, and C-Si in the polymer while reducing the thickness of the polymer layer. However, the increase of the overetch percentage from 50% to 100% did not change the composition of the polymer layer and the carbon bondings in the polymer layer remained same even though it increased the polymer thickness. The polymer layer formed at the higher dc-self bias voltage was more difficult to be removed by the following various post-etch treatments compared to that formed at the longer overetch percentage.

• Korean Chemical Engineering Research
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• 제54권4호
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• pp.548-554
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• 2016

Damascene 구조를 갖는 반도체소자의 구리금속배선 식각공정에서 배선재료에 의해서 발생되는 구리 식각잔류물을 제거하기 위해 oxalic acid (OA), lactic acid (LA) 및 citric acid (CA)의 카르복시산 함유된 반수계 혼합세정액을 제조하고 특성을 분석하였다. 카르복시산은 pH에 따라 카르복실기와 구리이온들과의 다양한 복합체를 형성하며 세정특성의 변화를 준다. 카르복시산들이 함유된 각각의 세정액의 세정특성평가결과 10 wt% CA를 함유한 반수계 세정액의 식각잔류물 세정특성은 pH 2에서 7까지의 영역에서 가장 낮은 구리 식각률을 보였으며 pH 2에서 4까지 구리에 대한 구리산화물의 가장 높은 식각 선택도를 나타내었으나 pH 5에서 7 범위에서는 10 wt% LA가 함유된 세정액이 더 높은 선택도를 보였다. 따라서 표면세정효과는 pH에 따라 변화하며 적절한 카르복시산을 사용함이 요구된다. CA가 함유된 세정액의 경우에 CA 농도와 구리에 대한 구리산화물의 식각 선택도의 증가특성을 보이며 CA가 5 wt%이상 함유된 경우에는 세정 후 구리배선의 표면이 88 %이상의 금속구리로 분석되어 구리산화물로 구성된 식각 잔류물의 제거에 효과적임을 알 수 있었다.