• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.27 no.1
• /
• pp.39-44
• /
• 2014

Silicon nitride thin film deposited with Plasma Enhanced Chemical Vapor Deposition was treated by a nitrogen plasma generated by Inductively Coupled Plasma at room temperature. The treatment was investigated by Fourier Transform Infrared Spectroscopy and Atomic Force Microscopy on the surface at various RF source powers at two RF bias powers. The amount of hydrogen was reduced and the surface roughness of the films was decreased remarkably after the plasma treatment. In order to understand the causes, we analyzed the plasma diagnostics by Optical Emission Spectroscopy and Double Langmuir Probe. Based on these analysis results, we show that the nitrogen plasma treatment was effective in the improving of the properties silicon nitride thin film for flexible display.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.18 no.11
• /
• pp.1001-1006
• /
• 2005

A new fabrication method is proposed to form the stacked polysilicon gate by nitridation in $N_2$ atmosphere using conventional LP-CVD system. Two step stacked layers with an amorphous layer on top of a polycrystalline layer as well as three step stacked layers with polycrystalline films were fabricated using the proposed method. SIMS profile showed that the proposed method would successfully create the nitrogen-rich layers between the stacked polysilicon layers, thus resulting in effective retardation of dopant diffusion. It was observed that the dopants in stacked films were piled-up at the interface. TEM image also showed clear distinction of stacked layers, their plane grain size and grain mismatch at interface layers. Therefore, the number of stacked polysilicon layers with different crystalline structures, interface position and crystal phase can be easily controlled to improve the device performance and reliability without any negative effects in nano-scale CMOSFETs.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.386-386
• /
• 2013

반도체 소자의 소형화, 고집적화로 박막의 다층화 및 선폭의 감소 등의 복잡한 제조 공정이 불가피하고, 따라서 공정 중 실리콘 웨이퍼와 금속 박막사이의 확산을 방지하기 위한 많은 연구가 이루어지고 있다. 하지만 현재까지의 연구는 확산방지막의 nano-mechanics 특성 분석에 대한 연구는 전무하다. 본 논문에서 tungsten (W)을 주 물질로, nitrogen (N)을 첨가한 확산방지막을 질소 유량을 2.5, 5, 7.5, 10 sccm으로 변화시켜가면서 rf magnetron sputter 방법으로 tungsten-nitride (W-N) 박막을 증착하였다. 박막의 기본 물성인 증착율, 비저항 및 결정학적 특성을 ${\beta}$-ray, 4-point probe, X-ray diffraction (XRD)를 이용하여 측정하였고, 측정결과 증착 중 질소 유량이 증가할수록 W-N 박막의 비저항은 증가하였고 반대로 증착율과 결정성은 감소하였다. 이는 기존의 연구 결과와 비교하여 일치한 결과로 증착된 박막이 신뢰성을 가짐을 확인하였다. 이후 가장 관심사인 nano-mechanics 특성은 nano-indenter를 이용하여 측정하였다. 측정 결과 시료는 증착 중 질소 유량이 2.5 sccm인 시료를 기준으로 5 sccm 포함된 박막에서 load force-depth 그래프가 급격히 변화하는 경향을 나타내었고, 표면강도(surface hardness)는 10.07 GPa에서 15.55 GPa로 증가하였다. 이후 질소 유량이 7.5 sccm과 10 sccm에서는 12.65 GPa와 12.77 GPa로 질소 유량이 5 sccm 포함된 박막보다 상대적으로 감소하였다. 이는 박막내 결정상으로 존재하는 질소와 비정질 상태로 존재하는 질소의 비율에 의한 것이고, 압축력에 기인하는 스트레스 증가로 판단된다.

• Korean Journal of Materials Research
• /
• v.10 no.4
• /
• pp.276-281
• /
• 2000

Silicon carbide(SiC) films were grown on modified Si(111) surface with a SiNx in the NH$_3$surrounding. Thickness of SiC films was decreased with increasing of the nitridation time. Also, voids having crystal defects were removed at interface of SiC/Si according to growth parameters. SiC films were grown on SiNx/Si substrate of 100, 300 and 500nm thickness. SiC films were deposited along [111] direction and columnar grains of SiC crystal. The void-free film was observed in the interface of SiC/SiNx. This result suggests that fabrication of SiC devices are applied to SiNx replacing silicon oxide in SOI structure.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.15 no.3
• /
• pp.252-259
• /
• 1990

This paper present new scheme for a Side Wall Masked Isolation(SWAMI) technology which take all the advatages provided by conventional LOCOS process. A new SWAMI process incorporates a sloped sidewall by reactive ion etch and a layer of thin nitride around the side walls such that both intrinsic nitride stress and volume expansion induced stress are greatly reduced. As a fabricate results, a defect-free fully recessed zero bird's beak local oxidation process can be realized by the sloped wall anisotropic oxide isolation. No additional masking step is required. The leakage current of PN diodes of this process were reduced than PN diode of conventional LOCOS process. On the other hand, the edge junction part was larger than the flat juction part in the density of leakage current.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.07a
• /
• pp.111-114
• /
• 2000

Growth characteristics and microstructure of AlN thin films grown by plasma assisted molecular beam epitaxy on Si substrates have been investigated. Growing temperature and substrate orientation were chosen as major variables of the experiment. Reflection high energy electron diffraction (RHEED), X-ray diffraction (XRD), atomic force microscopy (AFM) and transmission electron microscopy/diffraction (TEM/TED) techniques were employed to characterize the microstructure of the films. On Si(100) substrates, AlN thin films were grown along the hexagonal c-axis preferred orientation at temperature range 850-90$0^{\circ}C$. However on Si(111), the AlN films were epitaxially grown with directional coherency in AlN(0001)/Si(111), AlN(1100)/Si(110), and AlN(1120)/Si(112) at 85$0^{\circ}C$ and the epitaxial coherencry seemed to be slightly distorted with increasing temperature. The microstructure of AlN thin films on Si(111) substrates showed that the films include a lot of crystal defects and there exist micro-gaps among the columns.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.55 no.12
• /
• pp.565-569
• /
• 2006

Plasma enhanced chemical vapor deposition(PECVD) is a well established technique for the deposition of hydrogenated film of silicon nitride (SiNx:H), which is commonly used as an antireflection coating as well as passivating layer in crystalline silicon solar cell. PECVD-SiNx:H films were investigated by varying the deposition and annealing conditions to optimize for the application in silicon solar cells. By varying the gas ratio (ammonia to silane), the silicon nitride films of refractive indices 1.85 - 2.45 were obtained. The film deposited at $450^{\circ}C$ showed the best carrier lifetime through the film deposition rate was not encouraging. The film deposited with the gas ratio of 0.57 showed the best carrier lifetime after annealing at a temperature of $800^{\circ}C$. The single crystalline silicon solar cells fabricated in conventional industrial production line applying the optimized film deposition and annealing conditions on large area substrate of size $125mm{\times}125mm$ (pseudo square) was found to have the conversion efficiencies as high as 17.05 %. Low cost and high efficiency silicon solar cells fabrication sequence has also been explained in this paper.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.07b
• /
• pp.693-696
• /
• 2004

For InGaP/GaAs HBT applications, we have developed characterized MIM capacitors with thin $1000{\AA}$ PECVD silicon nitride which were deposited with $SiH_4/NH_3$ gas mixing rate, working pressure, and RF power of PECVD at $300^{\circ}C$ and had the capacitance density of 600 pF/$mm^2$ with the breakdown electric fields of 3073 MV/cm. Three PECVD process parameters were designed to lower the refractive index and then lower the deposition rate of silicon nitride films for the high breakdown electric field. At the PECVD process condition of gas mixing rate (0.92), working pressure (1.3 Torr), RF power (53 W), the AFM Rms value of about $1000{\AA}$ silicon nitride on the bottom metal was the lowest of 0.662 nmand breakdown electric fields were the highest of about 73 MV/cm.

• Korean Journal of Materials Research
• /
• v.4 no.1
• /
• pp.63-74
• /
• 1994

The ultrathin oxide films less than 100$\AA$ were grown by thermal oxidation in $N_2O$ ambient to improve the controllability of thickness, thickness uniformity, process reproducibility and their electrical properties. Oxidation rate was reduced significantly at very thin region due to the formation of oxynitride layer in $N_2O$ ambient and moreover nitridation of the oxide layer was simultaneously accompanied during growth. The nitrogen incorporation in the grown oxide layer was characterized with the wet chemical etch-rate and ESCA analysis of the grown oxide layer. All the oxides thin films grown in $N_2O$, pure and dilute $O_2$ ambients show Fowler-Nordheim electrical conduction. The electrical characteristics of thin oxide films grown in $N_2O$ such as leakage current, electrical breakdown, interface trap density generation due to the injected electron and reliability were better than those in pure or dilute ambient. These improved properties can be explained by the fact that the weak Si-0 bond is reduced by stress relaxation during oxidation and replacement by strong Si-N bond, and thus the trap sites are reduced.

• Korean Journal of Materials Research
• /
• v.3 no.5
• /
• pp.443-450
• /
• 1993

Self-alignment gatc Schottky contact structure on Si- implanted GaAs was formed by plasma enhanced chemical vapor dcposirion. Tungsten nitride thin films (ahclut 1600$\AA$) \vcre dopositcd on GaAs at $350^{\circ}C$ in order to fahricarc GaAs 1Cs and ttwn rapidly annealed at $750^{\circ}C$ to $900^{\circ}C$. Thermal charac tcristics of PECVD)-$W_{67}N_{43}$/GaAs structure were investigated by X-ray diffraction, photolumintesccnce. and optical deep level transient specrroscopy. Results revealed that $W_{67}N_{33}$ gate was more thermally sta ble with GaAs substrate than W gate and Si atoms implanted In $W_{67}N_{33}$/GaAs structure became morr active than those In W/GaAs after annealing. I-V characteristics of $W_{67}N_{33}$/GaAs diod c exhibired a nearly ideal diode behavior. The termal stability of $W_{67}N_{33}$/GaAs diode was better than that of W/GaAs diode with the post annealing at temperatures from 800 to $900^{\circ}C$ for 20s without As overpressure.