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

• ETRI Journal
• /
• 제36권2호
• /
• pp.214-223
• /
• 2014

A fully-integrated penta-band reconfigurable power amplifier (PA) is developed for handset Tx applications. The output structure of the proposed PA is composed of the fixed output matching network, power and frequency reconfigurable networks, and post-PA distribution switches. In this work, a new reconfiguration technique is proposed for a specific band requiring power and frequency reconfiguration simultaneously. The design parameters for the proposed reconfiguration are newly derived and applied to the PA. To reduce the module size, the switches of reconfigurable output networks and post-PA switches are integrated into a single IC using a $0.18{\mu}m$ silicon-on-insulator CMOS process, and a compact size of $5mm{\times}5mm$ is thus achieved. The fabricated W-CDMA PA module shows adjacent channel leakage ratios better than -39 dBc up to the rated linear power and power-added efficiencies of higher than around 38% at the maximum linear output power over all the bands. Efficiency degradation is limited to 2.5% to 3% compared to the single-band reference PA.

• 한국결정성장학회지
• /
• 제8권1호
• /
• pp.111-116
• /
• 1998

질화규소는 고경도, 고인성 세라믹 재료이기 때문에, 기계적 가공성은 매우 나쁘며, 또한 질화규소는 높은 전기 저항을 갖는다. 매우 높은 전기저항을 띠는 질화규소에 30wt% 이상의 TiN 분말이 첨가되었을 때 전도성 세라믹 복합체가 된다. 높은 전기 전도도를 가질 때 세라믹을 방전가공방법(EDM)을 이용하여 정밀한 가공을 할 수 있다. 높은 전기 전도도를 갖는 $Si_3N_4-TiN$ 세라믹 복합체는 EDM 방법을 이용하여 금속 가공 tool을 만드는데 이용되며, 이러한 tool 재료들은 산화뿐만 아니라 심각한 마모문제를 갖는다. 상압소결후 post HIP 소결방법으로 $Si_3N_4-TiN$ 복합체를 만들었으며, TiN의 양의 변화에 따른 $Si_3N_4$ 복합체의 마모특성을 상온의 대기중에서 조사하였다. 경도, 파괴인성, 강도값을 마모량과 비교하였다. 마모흔의 SEM 관찰로 $Si_3N_4-TiN$ 복합체의 마모기구를 설명하였다.

• Bulletin of the Korean Chemical Society
• /
• 제25권12호
• /
• pp.1859-1862
• /
• 2004

Europium doped yttrium vanadate ($YVO_4$:Eu) phosphor thin films were grown using a pulsed laser deposition (PLD) technique on silicon substrate. The structural characterization carried out on a series of ($YVO_4$:Eu films at post annealing temperature in the range of 550 $^{\circ}C$-1150 $^{\circ}C$ indicating that films were preferentially (200) oriented at post annealing temperature above 950 $^{\circ}C.$ Photoluminescence of thin film increased with the increase of post annealing temperature and ambient oxygen pressure though the thin film has the powder-like surface morphology at oxygen pressure above 200 mTorr. Photoluminescence decay from $^5D_1$ level of $Eu^{3+}$ show the great concentration dependency, which can be used as a good parameter to control the composition of ($YVO_4$:Eu thin film.

• 한국세라믹학회지
• /
• 제44권7호
• /
• pp.354-357
• /
• 2007

The nitriding and post-sintering behavior of silicon powder compact containing sintering additives of 2.3 wt% and 7 wt% were investigated in this study. Regardless of the liquid phase content, elongated large grains of a typical morphology evolved in the post-sintered specimens. Phase analysis revealed a complete phase transformation into ${\beta}-Si_3N_4$ in both porous systems. Oxynitride second phases (mellilite) precipitated in the latter, while those were free in the former containing less amount of liquid phase. The post-sintering condition that yielded a favorable microstructure for a filter application was achieved when the specimens were soaked at $1800^{\circ}C$ for 2 h. It was found that the thermal conductivity of porous $Si_3N_4$ ceramics is dominated by the porosity more than this factor is influenced by the addition of $Al_2O_3$.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2007년도 추계학술대회 논문집
• /
• pp.157-158
• /
• 2007

Effects of post-metallization anneal (PMA) on interface trap characteristics of Si-$SiO_2$ are studied. The conventional PMA method utilizes forming gas anneal, where 10% hydrogen in nitrogen atmosphere is used. A new PMA method utilizes hydrogen rich PECVD- silicon nitride $(SiN_x)$ film as a hydrogen diffusion source and a out-diffusion blocking layer. It can be shown through charge pumping current measurement that the new PMA is indeed effective to decrease Si-$SiO_2$ interface trap density.

• 한국재료학회지
• /
• 제19권3호
• /
• pp.174-178
• /
• 2009

The effects of post-CMP cleaning on the chemical and galvanic corrosion of copper (Cu) and titanium (Ti) were studied in patterned silicon (Si) wafers. First, variation of the corrosion rate was investigated as a function of the concentration of citric acid that was included in both the CMP slurry and the post-CMP solution. The open circuit potential (OCP) of Cu decreased as the citric acid concentration increased. In contrast with Cu, the OCP of titanium (Ti) increased as this concentration increased. The gap in the OCP between Cu and Ti increased as citric acid concentration increased, which increased the galvanic corrosion rate between Cu and Ti. The corrosion rates of Cu showed a linear relationship with the concentrations of citric acid. Second, the effect of Triton X-$100^{(R)}$, a nonionic surfactant, in a post-CMP solution on the electrochemical characteristics of the specimens was also investigated. The OCP of Cu decreased as the surfactant concentration increased. In contrast with Cu, the OCP of Ti increased greatly as this concentration increased. Given that Triton X-$100^{(R)}$ changes its micelle structure according to its concentration in the solution, the corrosion rate of each concentration was tested.

• 전자공학회논문지D
• /
• 제36D권10호
• /
• pp.23-30
• /
• 1999

본 논문에서는 전자선 직접 묘화 시스템을 이용하여 50 nm 이하의 패턴 폭을 가지는 패터닝 결과를 얻기 위한 실험을 수행하였다. SAL601 negative E-beam PR(Photo Resist)를 이용하여 실험을 진행하였고, E-beam 장비의 특성을 최대로 이용하기 위해서 PR의 두께를 100nm로 줄이고, field 크기를 200 ${um}m$로 줄여 실험하였으며, 또한 SAL601 PR의 경우 작은 선폭을 얻기 위해 중요한 요인 중에 하나인 PEB (Post Expose Bake) 온도와 시간을 줄이면서 실험을 진행하였다. 여기에 디지타이징 방식의 최적화를 통하여 50 nm 이하의 패턴 폭을 가지는 단선 패터닝 결과를 얻었다. 이 공정을 이용하여 단전자 메모리 소자에 응용 가능한 50 nm 급의 silicon 양자선과 silicon 양자점을 제작하였다. 이는 현재 많이 연구되고 있는 단전자 기억소자 및 국소 채널 MOS소자 제작에 유용할 것이다.

• Current Photovoltaic Research
• /
• 제5권2호
• /
• pp.63-67
• /
• 2017

Aluminum oxide ($Al_2O_3$) film deposited by atomic layer deposition (ALD) is known to supply excellent surface passivation properties on crystalline Si surface. The quality of passivation layer is important for high-efficiency silicon solar cell. double-layer structures have many advantages over single-layer materials. $Al_2O_3/SiN_X$ passivation stacks have been widely adopted for high- efficiency silicon solar cells. The first layer, $Al_2O_3$, passivates the surface, while $SiN_X$ acts as a hydrogen source that saturates silicon dangling bonds during annealing treatment. We explored the properties on passivation film of $Al_2O_3/SiN_X$ stack layer with changing the conditions. For the post annealing temperature, it was found that $500^{\circ}C$ is the most suitable temperature to improvement surface passivation.

• 전자공학회논문지A
• /
• 제33A권5호
• /
• pp.102-107
• /
• 1996

Use of a rapid thermal annealing (RTA) technique is shown to improve the properties of metal-ferroelectric BaMgF$_{4}$-silicon structures. The fluoride film was deposited in an ultra-high vacuum system at asubstrate temperature of 300$^{\circ}C$. A post-deposition annelaing was conducted for 10 seconds at 600.deg. C in a vacuum of 0.1 Torr, using a home-made RTA apparatus. The results showed that the resistivity of the ferroelectric BaMgF$_{4}$ film from a typical value of 1-2${\times}10^{11}{\Omega}{\cdot}cm$ before the annealing to about 5${\times}10^{13}{\Omega}{\cdot}cm$ and reduce the interface state density of the BaMgF$_{4}$/Si interface to about 8${\times}10^{10}cm^{2}{\cdot}$eV. Ferroelectric hysteresis measurements using a sawyer-tower circuit yielded remanent polarization and coercive field values of about 0.5$\mu$C/cm$^{2}$ and 80 kV/cm, respectively. the typical remanent polarization of the BaMgF$_{4}$ films ont he (100) and (111) oreientated silicon wafers were 0.5 - 0.6 $\mu$C/cm$^{2}$ and that of th efilms on the (110) wafers was 1.2$^{\circ}C$/cm$^{2}$.