• Journal of Information Display
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• 제2권3호
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• pp.60-65
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• 2001

Lateral type poly-silicon field emitters were fabricated by utilizing the LOCOS (Local Oxidation of Silicon) process. For the implementation 'of an ideal field emission device with quasi-zero tunneling barrier, a new and fundamental approach has used conducted by introducing an intelligent carbon-based thin layer on the cathode tip surface via a field-assisted self-aligning of carbon (FASAC) process. Fundamental lowering of the turn-on field for the electron emission was feasible through the control of both the tip shape and surface barrier height.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.1045-1048
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• 2007

We mainly report recent progress in backlight unit (BLU) for liquid crystal display (LCD) using printed carbon nanotubes (CNTs) including top-gate and lateral gate structures. Lighting performances of CNTBLU and longevity of printed CNT emitters are intensively discussed. Selected issues related with field emission display (FED) using the same emitters also are presented.

• JSTS:Journal of Semiconductor Technology and Science
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• 제2권2호
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• pp.93-101
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• 2002

We have proposed and fabricated two lateral type field emission diodes, poly-Si emitter by utilizing the local oxidation of silicon (LOCOS) and GaN emitter using metal organic chemical vapor deposition (MOCVD) process. The fabricated poly-Si diode exhibited excellent electrical characteristics such as a very low turn-on voltage of 2 V and a high emission current of $300{\;}\bu\textrm{A}/tip$ at the anode-to-cathode voltage of 25 V. These superior field emission characteristics was speculated as a result of strong surface modification inducing a quasi-negative electron affinity and the increase of emitting sites due to local sharp protrusions by an appropriate activation treatment. In respect, two kinds of procedures were proposed for the fabrication of the lateral type GaN emitter: a selective etching method with electron cyclotron resonance-reactive ion etching (ECR-RIE) or a simple selective growth by utilizing $Si_3N_4$ film as a masking layer. The fabricated device using the ECR-RIE exhibited electrical characteristics such as a turn-on voltage of 35 V for $7\bu\textrm{m}$ gap and an emission current of~580 nA/l0tips at anode-to-cathode voltage of 100 V. These new field emission characteristics of GaN tips are believed to be due to a low electron affinity as well as the shorter inter-electrode distance. Compared to lateral type GaN field emission diode using ECR-RIE, re-grown GaN emitters shows sharper shape tips and shorter inter-electrode distance.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2000년도 Proceedings of 5th International Joint Symposium on Microeletronics and Packaging
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• pp.110-110
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• 2000

Cantilever-shaped lateral field emitters were fabricated and their electrical characteristics were tested. As shown in Fig.1, poly-silicon cantilevers were fabricated by the surface micromachining and they were used to the vacuum magnetic field sensors. The tunneling devices were vacuum sealed with the tubeless packaging method, as shown in Fig.2 and Fig.3. The soda-lime glasses were used for better encapsulation, so the sputtered silicon and the glass layers on the soda-lime glasses were bonded together at 1x10$^{-6}$ Torr. The getter was activated after the vacuum sealing fur the stable emissions. The devices were tested outside of the vacuum chamber. Through vacuum packaging, the tunneling sensors can be utilized. Fig.4 shows that the sensor operates with the switching of the magnetic field. When the magnetic field was applied to the device, the anode currents were varied by the Lorentz force. The difference of anode currents can be varied with the strength of the applied magnetic field.

• 센서학회지
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• 제10권5호
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• pp.292-303
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• 2001

본 연구에서는 수평형 전계 방출 소자를 제작하고 그 특성을 측정하였다. 이를 진공자장 센서에 이용하기 위하여 Lorentz 원리를 응용하여 센서를 설계하고 제작하였다. $POCl_3(10^{20}cm^{-3})$ 도핑된 다결정 실리콘을 전계 방출 소자의 음극 및 양극 재료로 이용하였으며 그 두께는 각각 $2\;{\mu}m$였다. PSG(두께 $2\;{\mu}m$)를 희생층으로 사용하여 최종 단계에서 불산을 이용하여 제거하고 승화건조법을 이용하여 소자의 기판 점착 현상을 방지하였다. 제작된 소자를 유리기판 #1 위에 silver paste로 고정시키고 Cr 전극 패드와 와이어본딩 한 뒤 진공내에서 양극접합공정을 이용하여 소자를 $1.0{\times}10^{-6}\;Torr$에서 진공 실장하였다. 실장 후 게터를 활성화하여 내부진공도를 향상시켰다. 이렇게 패키징된 소자는 두달여 기간 동안 특별한 특성저하 없이 잘 동작되었으며 그 이상의 기간에 대해서는 확인하지 못하였다. 패키징된 자장 센서는 패키징하기 전 진공챔버 내에서 보인 특성치와 별다른 차이 없이 잘 동작되었으며 단지 약간의 전류 감소 현상만이 관찰되었다. 측정된 센서의 감도는 약 3%/T로서 작은 값이었으나 그 가능성을 확인할 수는 있었다.

• 한국농공학회지
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• 제31권2호
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• pp.104-115
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• 1989

In an effort to clarify the wetted patterns of sandy loam soil under trickle irrigation conditions, the distance of wetted zone, infiltration capacity and soil wetted patterns, etc. were measured by gypsum block as soil moisture sensor located every 5 cm vertically and horizontaly in the soil bin under the such conditions as a). irrigation rates set to 2, 4, 6, 8 liters per hour b). total amount of water applied fixed to 14.62 liters per soil bin c) the hearing force of soil measured by plate penetrometer ranging from 1.04 to 1.22kg/cm$_2$ The results can be summarized as follows ; 1. The wetted distance in horizontal direction(H), the wetted distance in vertical direction(D), the horizontal infiltration capacity (iH) and the vertical infiltration capacity(in)could by explained as a function of time t. 2. The horizontal wetted distance (H) is explained by an exponetial function H= a$.$ t where b was found ranging from 021 to 026 under surface trickle irrigation, which was considered a lotlower than the classical value of 0.5 and these measurements were indifferent to the increasing irrigation rates. 3. As for the surface trickle irrigation where horizontal infiltration capacity(iH) is explained as iH = A $.$ t h, the coefficient A increases with respect to irrigation rates within the limits of 0.89~1.34. 4. In terms of surface trickle irrigation of the ratio of Dm Which is maximum vertical wetted distance to Hm, which is maximum horizontal wetted distance, found to be within range of 1.0 to 1.21. It was also noted that the value of Dm decreses when irrigation rates increases while the value of Hm changes the opposite direction. 5. The optimum location of sensors from emitter for surface trickle irrigation should he inside of hemisphere whose lateral radius is 28~30cm long and vertical radius is 10~12cm long. The distance between emitters should be within 60cm long. 6. In the study of vertical wetted distance( D) where D= a $.$ tb, the exponential coefficient b ranged from 0.61 to 0.75 in surface trickle irrigation, and from 0A9 to 0.68 for subsurface trickle irrigation. These measurements showed an increasing tendency to with respect to irrigation rates. 7. In case of vertical infiltration capacity( in), where iD= A $.$ t 1-h, the coefficient A for surface trickle irrigation found to be within range of 0.16 to 0.19 and did not show any relationships with varying degree of irrigation rates. However, the coefficient was varying from 0.09 to 0.22 and showed a tendency to increase vis-a-vis irrigation rates for subsurface trickle irrigation, in contrast. 8. In the observation of subsurface trickle irrigation, it was found that Dm/Hm ratio was within 1.52 to 1.91 and showed a decreasing tendency with respect to increasing rates of irrigation. 9. The location of sensors for subsurface trickle irrigation follows same pattern as above, with vertical distance from emitter being 10~17cm long and horizontal 22~25cm long. The location of emitter should be 50 cm. 10.The relationship between VS which is the volume of wetted soil and Q which is the total amount of water when soil is reached field capacity could be explained as VS= 2.914Q0.91and the irrigation rates showed no impacts on the above relationship.