• 제목/요약/키워드: Shallow trench Isolation

검색결과 92건 처리시간 0.032초

Performance and Variation-Immunity Benefits of Segmented-Channel MOSFETs (SegFETs) Using HfO2 or SiO2 Trench Isolation

  • Nam, Hyohyun;Park, Seulki;Shin, Changhwan
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제14권4호
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    • pp.427-435
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    • 2014
  • Segmented-channel MOSFETs (SegFETs) can achieve both good performance and variation robustness through the use of $HfO_2$ (a high-k material) to create the shallow trench isolation (STI) region and the very shallow trench isolation (VSTI) region in them. SegFETs with both an HTI region and a VSTI region (i.e., the STI region is filled with $HfO_2$, and the VSTI region is filled with $SiO_2$) can meet the device specifications for high-performance (HP) applications, whereas SegFETs with both an STI region and a VHTI region (i.e., the VSTI region is filled with $HfO_2$, and the STI region is filled with $SiO_2$) are best suited to low-standby power applications. AC analysis shows that the total capacitance of the gate ($C_{gg}$) is strongly affected by the materials in the STI and VSTI regions because of the fringing electric-field effect. This implies that the highest $C_{gg}$ value can be obtained in an HTI/VHTI SegFET. Lastly, the three-dimensional TCAD simulation results with three different random variation sources [e.g., line-edge roughness (LER), random dopant fluctuation (RDF), and work-function variation (WFV)] show that there is no significant dependence on the materials used in the STI or VSTI regions, because of the predominance of the WFV.

Flowable oxide CVD Process for Shallow Trench Isolation in Silicon Semiconductor

  • Chung, Sung-Woong;Ahn, Sang-Tae;Sohn, Hyun-Chul;Lee, Sang-Don
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제4권1호
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    • pp.45-51
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    • 2004
  • We have proposed a new shallow trench isolation (STI) process using flowable oxide (F-oxide) chemical vapor deposition (CVD) for DRAM application and it was successfully developed. The combination of F-oxide CVD and HDP CVD is thought to be the superior STI gap-filling process for next generation DRAM fabrication because F-oxide not only improves STI gap-filling capability, but also the reduced local stress by F-oxide in narrow trenches leads to decrease in junction leakage and gate induced drain leakage (GIDL) current. Finally, this process increased data retention time of DRAM compared to HDP STI. However, a serious failure occurred by symphonizing its structural dependency of deposited thickness with poor resistance against HF chemicals. It could be suppressed by reducing the flow time during F-oxide deposition. It was investigated collectively in terms of device yield. In conclusion, the combination of F-oxide and HDP oxide is the very promising technology for STI gap filling process of sub-100nm DRAM technology.

미세 표면 구조물을 갖는 패드의 제작 및 STI CMP 특성 연구 (Development of Microstructure Pad and Its Performances in STI CMP)

  • 정석훈;정재우;박기현;서현덕;박재홍;박범영;주석배;최재영;정해도
    • 한국전기전자재료학회논문지
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    • 제21권3호
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    • pp.203-207
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    • 2008
  • Chemical mechanical polishing (CMP) allows the planarization of wafers with two or more materials. There are many elements such as slurry, polishing pad, process parameters and conditioning in CMP process. Especially, polishing pad is considered as one of the most important consumables because this affects its performances such as WIWNU(within wafer non-uniformity) and MRR(material removal rate). In polishing pad, grooves and pores on its surface affect distribution of slurry, flow and profile of MRR on wafer. A subject of this investigation is to apply CMP for planarization of shallow trench isolation structure using microstructure(MS) pad. MS pad is designed to have uniform structure on its surface and manufactured by micro-molding technology. And then STI CMP performances such as pattern selectivity, erosion and comer rounding are evaluated.

마이크로 표면 구조물을 갖는 패드의 STI CMP 특성 연구 (A Study on STI CMP Characteristics using Microstructure Pad)

  • 정재우;박기현;장원문;박선준;정문기;정해도
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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    • pp.356-357
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    • 2005
  • Chemical mechanical polishing (CMP) allows the planarization of wafers with two or more materials at their surfaces. Especially, polishing pad is considered as one of the most important consumables because of its properties. Subject of this investigation is to apply CMP for planarization of shallow trench isolation structure using microstructure pad. Microstructure pad is designed to have uniform structure on its surface and fabricated by micro-molding technology. And then STI CMP performances such as oxide dishing and nitride corner rounding are evaluated.

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A Study on the Electrical Characteristics of Ultra Thin Gate Oxide

  • Eom, Gum-Yong
    • Transactions on Electrical and Electronic Materials
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    • 제5권5호
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    • pp.169-172
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    • 2004
  • Deep sub-micron device required to get the superior ultra thin gate oxide characteristics. In this research, I will recommend a novel shallow trench isolation structure(STI) for thin gate oxide and a $N_2$O gate oxide 30 $\AA$ by NO ambient process. The local oxidation of silicon(LOCOS) isolation has been replaced by the shallow trench isolation which has less encroachment into the active device area. Also for $N_2$O gate oxide 30 $\AA$, ultra thin gate oxide 30 $\AA$ was formed by using the $N_2$O gate oxide formation method on STI structure and LOCOS structure. For the metal electrode and junction, TiSi$_2$ process was performed by RTP annealing at 850 $^{\circ}C$ for 29 sec. In the viewpoints of the physical characteristics of MOS capacitor, STI structure was confirmed by SEM. STI structure was expected to minimize the oxide loss at the channel edge. Also, STI structure is considered to decrease the threshold voltage, result in a lower Ti/TiN resistance( Ω /cont.) and higher capacitance-gate voltage(C- V) that made the STI structure more effective. In terms of the TDDB(sec) characteristics, the STI structure showed the stable value of 25 % ~ 90 % more than 55 sec. In brief, analysis of the ultra thin gate oxide 30 $\AA$ proved that STI isolation structure and salicidation process presented in this study. I could achieve improved electrical characteristics and reliability for deep submicron devices with 30 $\AA$ $N_2$O gate oxide.

Oxide CMP 공정의 최적화에 관한 연구 (Optimizations for oxide CMP processes)

  • 김동일;허종곤;윤각기;이종구
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1998년도 하계종합학술대회논문집
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    • pp.481-484
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    • 1998
  • In this study, oxide(TEOS) CMPs were carried out for various head pressures. Table and head speeds are fixed at 25 RPM. Head pressures are 5, 7.5, 10, 12.5 PSI, and under these conditions, 1,587, 1,631, 2,556, 2,871.agns./min of oxide (TEOS) removal rates and 14.7, 18.5, 9.52, 7.9% of uniformities are obtained, respectively. Also, these experiments for local and global planarizations were done using the patterned 4" wafers. These conditions are applicable to STI(shallow trench isolation) structures and planarizations for sub-half micron lithography.aphy.

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