• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2267-2271
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• 2011

This study was focused on getting p-type copper-oxide thin-film semiconductors suitable for p-channel thin-film transistors. Vacuum thermal evaporation and thermal annealing were used to get copper-oxide thin-film semiconductor having properties adoptable as an active layer of thin-film transistors. n-type thin films having electron carrier density of about $10^{22}\;cm^{-3}$ before thermal annealing was converted to p-type thin films having hole carrier density of about $10^{16}\;cm^{-3}$ as the thermal annealing conditions were optimized.

• Journal of Magnetics
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• v.12 no.4
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• pp.144-148
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• 2007

We report on the observation of p-type conductivity and ferromagnetism in diluted magnetic semiconductor $(Zn_{0.97}Mg_{0.01}Mn_{0.02})O:P$ films grown on $SiO_2/Si$ substrates by pulsed laser deposition. The p-type conduction with hole concentration over $10^{18}cm^{-3}$ is obtained by codoping of Mg and P followed by rapid thermal annealing in an $O_2$ atmosphere. Structural and compositional analyses for the p-type $(Zn_{0.97}Mg_{0.01}Mn_{0.02})O:P$ films annealed at $800^{\circ}C$ indicates that highly c-axis oriented homogeneous films were grown without any detectable formation of secondary phases. The films were found to be transparent in the visible range. The magnetic measurements clearly revealed an enhancement of room temperature ferromagnetism by p-type doping.

• Journal of the Semiconductor & Display Technology
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• v.4 no.2 s.11
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• pp.1-5
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• 2005

Electon spin resonance measurements have been performed on the Mg-doped wurtzite GaN thin films grown on sapphire substrates by low-pressure metal-organic chemical vapor deposition. The sample set included films as-grown with the regular Mg doped and Mg delta doped samples and the corresponding annealed ones. The resonance signal has been observed from the annealed Mg delta-doped sample with the Lande g value of 2.029. This indicates that the singlet resonance signal originates from the neutral Mg acceptor located at 0.24 eV above the valence band edge and 0.13 eV above the Fermi level because of the nuclear hyperfine spin 1=0 of Mg and the larger value than the free electron g=2.0023.

• Journal of Biomedical Engineering Research
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• v.22 no.2
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• pp.145-150
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• 2001

대뇌 피질에 삽입하여 깊이에 따라 신경 신호를 기록하기 위한 탐침형 반도체 미세전극 어레이(depth-type silicon microelectrode array, 일명 SNU probe)를 제작하였다. 붕소를 확산시켜 생성된 고농도 p-type doping된 p＋ 영역을 습식식각 정지점으로 사용하는 기존의 방법과 달리 실리콘 웨이퍼의 앞면을 건식식각하여 원하는 탐침 두께만큼의 깊이로 트렌치(trench)를 형성한 후 뒷면을 습식식각하는 방법으로 탐침 형태의 미세 구조를 만들었다. 제작된 반도체 미세전극 어레이의 탐침 두께는 30 $\mu\textrm{m}$이며 실리콘 건식식각을 위한 마스크로 6 $\mu\textrm{m}$ 두께의 LTO(low temperature oxide)를 사용하였다. 탐침의 두께는 개발된 본 공정을 이용해서 5~90 $\mu\textrm{m}$ 범위까지 쉽게 조절할 수 있었다. 탐침의 두께를 보다 쉽게 조절할 수 있게 됨에 따라 여러 신경조직에 필요한 다양한 구조의 반도체 미세전극 어레이를 개발할 수 있게 되었다. 본 공정을 이용해서 개발된 4채널 SUN probe를 사용하여 흰쥐의 제1차 체감각 피질에서 4채널 신경 신호를 동시에 기록하였으며, 전기적 특성검사에서 기존의 탐침형 반도체 미세전극, 텅스텐 전극과 대등하거나 우수한 신호대 잡음비(signal to noise ratio, SNR)특성을 가짐을 확인하였다.

• Journal of Korean Vacuum Science & Technology
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• v.6 no.2
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• pp.58-61
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• 2002

Photoluminescence up-conversion in semiconductor heterostructures is a phenomenon in which luminescence occurs at energies higher than that of the excitation photons. It has been observed in many semiconductor heterostructure systems, including InP/AnALAs, CdTe/CdMgTe, GaAs/ordered-(Al)GalnP, GaAs/AIGaAs, and InAs/GaAs. In this wort, GaAs/AIGaAs heterostructures are used as a model system to study the mechanism of the up-conversion process. This system is ideal for testing different models because the band offsets are quite well documented. Different heterostructures are designed to study the effect of disorder on the up-converted luminescence efficiency. In order to study the roles of different types of carriers, the effect of doping was investigated. It was found that the up-converted luminescence is significantly enhanced by p-type doping of the higher-band-gap material.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.726-728
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• 1998

Optical and electrical properties of GaSe:$Er^{3+}$ single crystals grown by the Bridgeman technique was been investigated by using optical absorption and Hall-effect measurements. The Hall coefficients were measured by using a high impedance electrometer in the temperature range from 360K to 150K. The temperature dependence of hole concentration shows the characteristic of a partially compensated p-type semiconductor. carrier density($N_H$) of GaSe doped with Erbium was measured about $3.25{\times}10^{16}\;[cm^{-3}}$ at temperature 300K, which was high than undoped specimen. Photon energy gap ($E_{gd}$) was measured about 1.7geV.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.1
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• pp.1-5
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• 2000

Optical and electrical properties of GaSe:Er\ulcorner single crystals grown by the Bridgenman technique have been investigated by using optical absorption and h\Hall-effect measurement system. The Hall coefficients were mea-sured by using a high impedance electrometer in the temperature range from 360K to 150K. The temperature dependence of hole concentration show the characteristic of a partially compensated p-type semiconductor. Carrier density(N\ulcorner) of GaSe doped with Erbium was measured about 3.25$\times$10\ulcorner [cm\ulcorner] at temperature 300K, which was higher than undoped specimen. Photon energy gap (E\ulcorner) of GaSe:Er\ulcorner specimen was measured about 1.79eV.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.206-209
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• 2002

With the progress of semiconductor processing technology, avalanohe photodiodes (APDs) based on InP/InGaAs are used for high-speed optical receiver modules. Planar-type APDs give higher reliability than mesa-type APDs. However, Planar-type APDs are struggled with a problem of intensed electric field at the junction curvature, which causes edge breakdown phenomena at the junction periphery. In this paper, we focused on studying the effects of junction curvature for APDs performances by different etching processes followed by single diffusion to from p-n junction. The performance of each process is characterized by observing electric field profiles and carrier generation rates. From the results, it can be understood to predict the optimum structure, which can minimize edge breakdown and improve the manufacturability.

• Journal of IKEEE
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• v.25 no.3
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• pp.467-472
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• 2021

Stable operation of semiconductor devices is needed even at high temperatures. Among the structures of semiconductor devices, the area that can cause unstable electrical responses at high temperatures is the contact layer between the metal and the semiconductor. In this study, the effect of annealing conditions included in the process of forming a contact layer of nickel silicide(NiSix) on a p-type SiC layer on the specific contact resistance of the contact layer and the total resistance between the metal and the semiconductor was investigated. To this end, a series of electrodes for TLM (transfer length method) measurements were patterned on the 4 inch p-type SiC layer under conditions of changing annealing temperature of 1700 and 1800 ℃ and annealing time of 30 and 60 minutes. As a result, it was confirmed that the annealing conditions affect the resistance of the contact layer and the electrical stability of the device.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1372-1373
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• 2006

An electrostatic discharge (ESD) protection device, so called, N-type SCR with P-type MOSFET pass structure (NSCR_PPS), was analyzed for high voltage I/O applications. A conventional NSCR_PPS device shows typical SCR-like characteristics with extremely low snapback holding voltage, which may cause latchup problem during normal operation. However, a modified NSCR_PPS device with proper junction/channel engineering demonstrates highly latchup immune current- voltage characteristics.