• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.600-600
• /
• 2013

We have fabricated Cr nanodot Schottky diodes utilizing AAO templates formed on n-Si substrates. Three different sizes of Cr nanodots (about 75.0, 57.6, and 35.8 nm) were obtained by controlling the height of the AAO template. Cr nanodot Schottky diodes showed a rectifying behavior with low SBHs of 0.17~0.20 eV and high ideality factors of 5.6~9.2 compared to those for the bulk diode. Also, Cr nanodot Schottky diodes with smaller diameters yield higher current densities than those with larger diameters. These electrical behaviors can be explained by both Schottky barrier height (SBH) lowering effects and enhanced tunneling current due to the nanoscale size of the Schottky contact. Also, we have fabricated Cr-Si nanorod Schottky diodes with three different lengths (130, 220, and 330 nm) by dry etching of n-Si substrate. Cr-Si nanorod Schottky diodes with longer nanorods yield higher reverse current than those with shorter nanorods due to the enhanced electric field, which is attributed to a high aspect ratio of Si nanorod.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.35D no.11
• /
• pp.70-77
• /
• 1998

Ni/SiC Schottky diodes have been fabricated using epitaxial 4H-SiC and 6H-SiC wafers. The epitaxial n-type layers were grown on $n^{+}$ substrates, with a doping density of 4.0$\times$10$^{16}$ c $m^{-3}$ and a thickness of 10${\mu}{\textrm}{m}$. Oxide-termination has been adopted in order to obtain high breakdown voltage and low leakage current. The fabricated Ni/4H-SiC and Ni/6H-SiC Schottky barrier diodes show excellent rectifying characteristics up to the measured temperature range of 55$0^{\circ}C$. In case of oxide-terminated Schottky barrier diodes, breakdown voltage of 973V(Ni/4H-SiC) and 920V(Ni/6H-SiC), and a very low leakage current of less than 1nA at -800V has been observed at room temperature. On non-terminated Schottky barrier diodes, breakdown voltages were 430V(Ni/4H-SiC) and 160v(Ni/6H-SiC). At room temperature, SBH(Schottky Barrier Height), ideality factor and specific on-resistance were 1.55eV, 1.3, 3.6$\times$10$^{-2}$ $\Omega$.$\textrm{cm}^2$ for Ni/4H-SiC Schottky barrier diodes, and 1.24eV, 1.2, 2.6$\times$10$^{-2}$$\Omega$.$\textrm{cm}^2$/ for Ni/SH-SiC Schottky barrier diodes, respectively. These results show that both Ni/4H-SiC and Ni/6H-SiC Schottky barrier diodes are very promising for high-temperature and high power applications.s..

• Proceedings of the IEEK Conference
• /
• 2006.06a
• /
• pp.591-592
• /
• 2006

Schottky diodes for Radio-frequency identification (RFID) tag integration on chip were designed and fabricated using Samsung electronics System LSI standard $0.18{\mu}m$ CMOS process. Schottky diodes were designed as interdigitated fingers array by CMOS layout design rule. 64 types of Schottky diode were designed and fabricated with the variation of finger width, length and numbers with a $0.6{\mu}m$ guard ring enclosing n-well. Titanium was used as Schottky contact metal to lower the Schottky barrier height. Barrier height of the fabricated Schottky diode was 0.57eV. DC current - voltage measurements showed that the fabricated Schottky diode had a good rectifying properties with a breakdown voltage of -9.15 V and a threshold voltage of 0.25 V.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.7
• /
• pp.774-779
• /
• 1988

The homo and hetero-junction diodes were fabricated using BP-Si structure. After removal of Si substrates, schottky diodes were fabricated on the BP bulk. The electrical properties of the diode were examined through current-voltage characteristics curve. The schottky diode with Sb electrode has a cut-in voltage of 0.33V. This value is almost equal to that of the typical schottky diodes. The breakdown voltage of the schottky diode is 30V. When BP was used for photo cell as a window, the conversion efficiency improved from 6.5% to 8.3%, and optical transmissivity of BP invreased in short wavelength region.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.31A no.1
• /
• pp.71-76
• /
• 1994

Schottky diodes have been fabricated using the SDB wafer, and their characteristics have been investigated. For comparison, conventional planar and etched most structure were made on the same substrate. The ideality factor and barrier height of the fabricated devices are found to be 1.03 and 0.77eV, respectively. Breakdown volttge of the etched mesa Schottky diode has been increased to 180V. whereas it is 90V for the planar diode. Schottky diode with an etched mesa exhibits twice improvement in breaktown voltage.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 1999.05a
• /
• pp.40-40
• /
• 1999

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.19 no.9
• /
• pp.818-824
• /
• 2006

The effects of high-temperature process required to fabricate the SiC devices on the surface morphology and the electrical characteristics were investigated for 4H-SiC Schottky diodes. The 4H-SiC diodes without a graphite cap layer as a protection layer showed catastrophic increase in an excess current at a forward bias and a leakage current at a reverse bias after high-temperature annealing process. Moreover it seemed to deviate from the conventional Schottky characteristics and to operate as an ohmic contact at the low bias regime. However, the 4H-SiC diodes with the graphite cap still exhibited their good electrical characteristics in spite of a slight increase in the leakage current. Therefore, we found that the graphite cap layer serves well as the protection layer of silicon carbide surface during high-temperature annealing. Based on a closer analysis on electric characteristics, a conductive surface transfiguration layer was suspected to form on the surface of diodes without the graphite cap layer during high-temperature annealing. After removing the surface transfiguration layer using ICP-RIE, Schottky diode without the graphite cap layer and having poor electrical characteristics showed a dramatic improvement in its characteristics including the ideality factor[${\eta}$] of 1.23, the schottky barrier height[${\Phi}$] of 1.39 eV, and the leakage current of $7.75\{times}10^{-8}\;A/cm^{2}$ at the reverse bias of -10 V.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.08a
• /
• pp.305-305
• /
• 2010

It is known that a pulse of electrons of high kinetic energy (1-3 eV) in metals can be generated with the deposition of external energy to the surface such as in the absorption of light or in exothermic chemical processes. These energetic electrons are not in thermal equilibrium with the metal atoms and are called "hot electrons" The concept of photon energy conversion to hot electron flow was suggested by Eric McFarland and Tang who directly measured the photocurrent on gold thin film of metal-semiconductor ($TiO_2$) Schottky diodes [1]. In order to utilize this scheme, we have fabricated metal-semiconductor Schottky diodes that are made of Pt or Au as a metallic layer, Si or $TiO_2$ as a semiconducting substrate. The Pt/$TiO_2$ and Pt/Si Schottky diodes are made by PECVD (Plasma Enhanced Chemical Vapor Deposition) for $SiO_2$, magnetron sputtering process for $TiO_2$, e-beam evaporation for metallic layers. Metal shadow mask is made for device alignment in device fabrication process. We measured photocurrent on Pt/n-Si diodes under AM1.5G. The incident photon to current conversion efficiency (IPCE) at different wavelengths was measured on the diodes. We also show that the steady-state flow of hot electrons generated from photon absorption can be directly probed with $Pt/TiO_2$ Schottky diodes [2]. We will discuss possible approaches to improve the efficiency of photon energy conversion.

• Journal of the Semiconductor & Display Technology
• /
• v.14 no.1
• /
• pp.27-30
• /
• 2015

SiC based Schottky barrier diodes were prepared by using the facing targets sputtering method. In this research, 4H-SiC polytypes of SiC were adopted and Molybdenum, Titanium was employed as the Schottky metal of the metal-semiconductor contacts. Both structures showed the rectifying nature in their forward and reverse J-V characteristic curve and the ideality factors calculated from these plots that were close to unity were represented the nearly ideal behavior. Difference of Schottky barrier height between prepared devices was also corresponding with the electrical characteristics of themselves. Therefore the suitability of the facing targets sputtering method for fabrication of Schottky diodes could be suggested from these results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.275-275
• /
• 2008

This paper describe the fabrication of a Pd/polycrystalline 3C-SiC schottky diode and its characteristics, in which the polycrystalline 3C-SiC layer and Pd Schottky contact were deposited by using APCVD and sputter, respectively. Crystalline quality, uniformity, and preferred orientations of the Pd thin film were evaluated by SEM and XRD, respectively. Pd/poly 3C-SiC Schottky diodes were fabricated and characterized by I-V and C-V measurements. Its electric current density Js and barrier height voltage were measured as $2\times10^{-3}$ A/$cm^2$ and 0.58 eV, respectively. These devices were operated until about $400^{\circ}C$. Therefore, from these results, Pd/poly 3C-SiC Schottky devices have very high potential for high temperature chemical sensor applications.