• Title/Summary/Keyword: STI

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A Study for the Improvement of Torn Oxide Defect in STI(Shallow Trench Isolation)Process (STI(Shallow Trench Isolation) 공정에서 Torn Oxide Defect 해결에 관한 연구)

  • Kim, Sang-Yong;Seo, Yong-Jin;Kim, Tae-Hyung;Lee, Woo-Sun;Chung, Hun-Sang;Kim, Chang-Il;Chang, Eui-Goo
    • Proceedings of the KIEE Conference
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    • 1998.11c
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    • pp.723-725
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    • 1998
  • STI CMP process are substituting gradually for LOCOS(Local Oxidation of Silicon) process to be available below sub-0.5um technology and to get planarized. The other hand, STI CMP process(especially STI CMP with RIE etch back process) has some kinds of defect like Nitride residue, Torn Oxide defect, etc. In this paper, we studied how to reduce Torn Oxide defects after STI CMP with RIE etch back process. Although Torn Oxide defects which occur on Oxide on Trench area is not deep and not sever, Torn oxide defects on Moat area is sometimes very deep and makes the yield loss. We did test on pattern wafers witch go through Trench process, APCVD process, and RIE etch back process by using an REC 472 polisher, IC1000/SUV A4 PAD and KOH base slurry to reduce the number of torn defects and to study what is the root causes of torn oxide defects.

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Preventing a Gate Oxide Thinning in C-MOS process Using a Dual Gate Oxide (Dual Gate Oxide 공정에서 Gate Oxide Thinning 방지에 대한 고찰)

  • Kim, Sung-Hoan;Kim, Jae-Wook;Sung, Man-Young
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07a
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    • pp.223-226
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    • 2003
  • We propose an improvement method for a $\underline{G}ate$ $\underline{OX}ide(GOX)$ thinning at the edge of $\underline{S}hallow$ $\underline{T}rench$ $\underline{I}solation(STI)$, when STI is adopted to Dual Gate Oxide(DGOX) Process. In the case of SOC(System On-a-Chip), the DGOX process is usually used for realizing both a low and a high voltage parts in one chip. However, it is found that the severe GOX thinning occurs from at STI top edge region and a dent profile exists at the top edge of STI, when conventional DGOX and STI process carried out in high density device chip. In order to overcome this problem, a new DGOX process is tried in this study. And we are able to prevent the GOX thinning by H2 anneal, partially SiN liner skip, and a method which is merged a thick sidewall oxide(S/O) with a SiN pull-back process. Therefore, a good subthreshold characteristics without a double hump is obtained by the prevention of a GOX thinning and a deep dent profile.

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Study of MOSFET Subthreshold Hump Characteristics by Phosphorous Auto-doping

  • Lee, Jun-Gi;Kim, Hyo-Jung;Kim, Gwang-Su;Choe, Byeong-Deok
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.319-319
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    • 2012
  • 현재 폭넓게 이용되고 있는 STI (Shallow Trench Isolation) 공정에서 active edge 부분에 발생하는 기생 transistor의 subthreshold hump 특성을 제어하는 연구가 활발히 이루어지고 있다. 일반적으로 STI 공정을 이용하는 MOSFET에서 active edge 부분의 얇게 형성된 gate oxide, sharp한 active edge 형성, STI gap-fill 공정 중에 생기는 channel dopant out-diffusion은 subthreshold hump 특성의 주된 요인이다. 이와 같은 문제점을 해결하기 위해 active edge rounding process와 channel dopant compensation의 implantation을 이용하여 subthresold hump 특성 개선을 연구하였다. 본 연구는 STI 공정에 필요한 wafer와 phosphorus를 함유한 wafer를 한 chamber 안에서 auto-doping하는 방법을 이용하여 subthresold hump 특성을 구현하였다. phosphorus를 함유한 wafer에서 빠져나온 phosphorus가 STI 공정중인 wafer로 침투하여, active edge 부분의 channel dopant인 boron 농도를 상대적으로 낮춰 active edge 부분의 가 감소하고 leakage current를 증가시킨다. transistor의 channel length, gate width이고, wafer#No가 클수록 phosphorous를 함유한 wafer까지의 거리는 가까워진다. wafer #01은 hump 특성이 없고, wafer#20은 에서 심한 subthreshold hump 특성을 보였다. channel length 고정, gate width를 ~으로 가변하여 width에 따른 영향을 실험하였다. active 부분에 대한 SCM image로 확인된 phosphorus에 의한 active edge 부분의 boron 농도 감소와 gate width vs curve에서 확인된 phosphorus에 의한 감소가 narrow width로 갈수록 커짐을 확인하였다.

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Rethinking Borders of National Systems of Innovation:Austrian Perspectives on Korea's Internationalization of Green Technologies

  • Olbrich, Philipp;Witjes, Nina
    • STI Policy Review
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    • v.5 no.2
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    • pp.65-95
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    • 2014
  • The recent decades have seen a growing rate of international cooperation in science, technology, and innovation (STI) including in the field of green technologies. However, current approaches to national systems of innovation (NSI) have not kept up with this development. International aspects are rather treated as external conditions within which policymakers operate and respond but not influence. This paper tackles this problem by applying a refined NSI concept that includes an international dimension and complements past frameworks by focusing on those Korean government policies, actors, and activities relevant for the internationalization of STI. Austria and Korea have both formulated differing strategies to acquire international leading positions in the field of innovation and the development of green technologies. In the first step, the paper assesses Korea's international activities within the field of green technologies that transcend national boundaries and establish international connections. The government has still a strong influence on selecting technology areas for strategic funding but our findings show that international STI actors have difficulties in identifying the appropriate point of contact to initiate cooperation or apply for related funding. Second, an external perspective on Korea's international collaborations in the field of green technologies is offered. Austria has tentatively identified the East Asian country as a second-priority cooperation partner for its future STI internationalization activities. Interviews with Austrian stakeholders in the field of green technologies indicate a high interest in cooperation with Korea that is facilitated by a similar business culture based on personal networks. Moreover, researchers and policymakers referred to a shared need of small countries for intelligent decision-making processes regarding potential cooperation partners abroad. However, in order to enhance awareness, visibility and demand for Korean STI cooperation in European countries, more long-term funding programs featuring a more permanent point of contact should be introduced.

Epidemiological Trends of Sexually Transmitted Infections Among Women in Cheonan, South Korea, 2011-2017 (2011년부터 2017년까지 천안에서의 STI 감염 양상)

  • Park, Ji On;Jeon, Jae-Sik;Kim, Jong Wan;Kim, Jae Kyung
    • Microbiology and Biotechnology Letters
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    • v.46 no.1
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    • pp.85-90
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    • 2018
  • Sexually transmitted infections (STIs) are a global health concern and can cause serious complications such as miscarriage, premature birth, and pelvic infection in pregnant women. Therefore, accurate diagnosis and information on the epidemiologic trends are critical. However, studies of STI trends in Cheonan, South Korea, have not been conducted since 2012. We examined the STI trends in the Cheonan area after 2012. From January 2011 to September 2017, 3,362 cervical swab specimens from female patients were sampled at the Dankook University Hospital and analyzed by multiplex PCR. Of the 3,362 specimens, 1,281 were positive for pathogens (38.92%). A total of 1,893 pathogens were detected. Ureaplasma urealyticum, Mycoplasma hominis, and Chlamydia trachomatis were the most frequent pathogens, accounting for 36.29% (687/1,893), 30.16% (571/1,893), and 19.97% (378/1,893) of the pathogen-positive samples, respectively. In the 2009-2012 analysis, M. hominis was identified as the predominant pathogen in STI samples, whereas U. urealyticum was identified as the major pathogen in this study. In many countries, including South Korea and the United States, the rate of STIs is increasing, while a decreasing trend was observed in Cheonan.

The Effects of Stage Reflectors on Stage Acoustics in Concert Halls (콘서트홀에서 무대음향에 대한 무대 반사판의 영향)

  • Kim, Yong-Hee;Kim, Su-Yeon;Jeon, Jin-Yong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.87-91
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    • 2005
  • The effects of the movable reflectors on the stage acoustics in Seoul's Sejong Performing Arts Center (3,048-seat multi-purpose hall, stage area of $270m^2$ within an orchestra shell) and Ceramic Palace Hall (440-seat concert hall, stage area of $105m^2$) were investigated. Acoustical parameters were evaluated by measuring stage and audience acoustics in the two halls. The study was primarily based on the stage support parameter STI proposed by Gade (Acustica 65, pp.193-203, 1989). Results showed that STI varied on the stage of the large hall according to the position of the reflectors, whereas STI did not vary in the small hall. In the large hall, a smaller clear stage area (bounded by the reflectors) yields an increase in both STI and other early energy measures. In the small hall, early energy decreases when its stage's surface diffusion was covered with specular reflectors.

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