• Proceedings of the Korean Vacuum Society Conference
• /
• 1997.02a
• /
• pp.33-33
• /
• 1997

• Proceedings of the Korean Vacuum Society Conference
• /
• 1994.06a
• /
• pp.142-143
• /
• 1994

• Proceedings of the Korean Vacuum Society Conference
• /
• 2008.08a
• /
• pp.43-43
• /
• 2008

• Proceedings of the Korean Vacuum Society Conference
• /
• 2002.06a
• /
• pp.191-193
• /
• 2002

• Proceedings of the Korean Vacuum Society Conference
• /
• 1996.02a
• /
• pp.119-119
• /
• 1996

• Proceedings of the Korean Vacuum Society Conference
• /
• 1996.02a
• /
• pp.153-153
• /
• 1996

• Proceedings of the Korean Vacuum Society Conference
• /
• 2007.02a
• /
• pp.165-165
• /
• 2007

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.02a
• /
• pp.403-404
• /
• 2012

We fabricated TFT devices with the GeSe channel. A single device consists of a Pt source and drain, a Ti glue layer and a GeSe chalcogenide channel layer on SiO2/Si substrate which worked as the gate. We confirmed the drain current with variations of gate bias and channel size. The I-V curves of the switching device are shown in Fig. 1. The channel of the device always contains amorphous state, but can be programmed into two states with different threshold voltages (Vth). In each state, the device shows a normal Ovonic switching behavior. Below Vth (OFF state), the current is low, but once the biasing voltage is greater than Vth (ON state), the current increases dramatically and the ON-OFF ratio is high. Based on the experiments, we draw the conclusion that the gate voltage can enhance the drain current, and the electric field by the drain voltage affects the amorphous-amorphous transition. The switching device always contains the amorphous state and never exhibits the Ohmic behavior of the crystalline state.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.08a
• /
• pp.280-281
• /
• 2011

We fabricated the devices of TFT type with the amorphous chalcogenide channel. A single device consists of a Pt source and drain, a Ti glue layer and a GeSe chalcogenide channel layer on SiO2/Si substrate which worked as the gate. We confirmed the drain current with variations of gate bias and channel size. The I-V curves of the switching device are shown in Fig. 1. The channel of the device always contains amorphous state, but can be programmed into two states with different threshold voltages (Vth). In each state, the device shows a normal Ovonic switching behavior. Below Vth (OFF state), the current is low, but once the biasing voltage is greater than Vth (ON state), the current increases dramatically and the ON-OFF ratio is about 4 order. Based on the experiments, we contained the conclusion that the gate voltage can enhance the drain current, and the electric field by the drain voltage affects the amorphous-amorphous transition. The switching device always contains the amorphous state and never exhibits the Ohmic behavior of the crystalline state.

• Journal of the Korean Vacuum Society
• /
• v.20 no.3
• /
• pp.165-175
• /
• 2011

This paper introduces statistical features observed from measured batch data from the multiple operation state variables of dry vacuum pumps running in the semiconductor processes. The amplitude distribution characteristics of such state variables as inlet pressures, supply currents of the booster and dry pumps, and exhaust pressures are shown to be divided into two or three distinctive regions. This observation gives an idea of using an adaptive parametric model (APM) chosen to describe their statistical features. This modelling, in comparison to the traditional dynamic time wrapping algorithm, is shown to provide superior performance in computation time and memory resources required in the preprocessing stage of sampled batch data for the diagnosis of running dry vacuum pumps. APM model-based batch data are demonstrated to be very appropriate for monitoring and diagnosing the running conditions of dry vacuum pumps.