閘極結構和鑽石形態對三極場效發射陣列電性之影響

Abstract

場效發射顯示器的發展將有希望成為製造下世代平面顯示器的重要技術之一。組成場效平面顯示器用的場發射陣列元件是由無數個可發射電子的場發射單元(FEC)配列所組成的畫素(pixel) 依陣列方式規則排列而成。在場發射顯示陣列中影響整個發射場功率的因素，包括發射尖端材料之外觀型態及其功函數、尖端與閘極間之距離或影響功函數的真空環境。然而鑽石的(111)面具有優異的負電子親和力特性，並擁有高電子移動性、高熱傳導係數與良好的化學穩定性。因此，鑽石將成為最具潛力之電子場發射元件之尖端材料。 在本論文中，我們製作一種新閘極結構之場發射顯示陣列，並成功的證實其可行性。首先必須使用IC製程技術製造金屬/絕緣層/半導體(MIS)結構元件，再利用成長鑽石膜之偏壓輔助微波電漿化學氣相沉積技術成功的製作出類柱狀型的鑽石場發射陣列元件。 另一方面，我們探討場發射陰極陣列的閘極結構和鑽石發射極形態對於場發射電流的影響。因此，將類柱狀型鑽石場發射陣列元件(場發射單元孔徑4 mm，閘極與矽基材間距為400 nm)和圓錐形鑽石場發射陣列元件(場發射單元孔徑8 mm，閘極距矽基材為700 nm)所測得之場發射電流性質的結果作比較與討論。 實驗結果顯示，類柱狀型鑽石場發射陣列元件在閘極電壓為20 V時之起始電壓約為10 V，其場發射電流約為 44 mA，場發射電流密度為139 mA/cm2；圓錐形鑽石場發射陣列元件在閘極電壓為50 V時之起始電壓約為12 V，場發射電流約為 130mA，其場發射電流密度為98 mA/cm2。由以上結果我們可推論其場發射陣列的的閘極結構與發射極形態對電子場發射特性具有相當的影響。

Field emission display (FED) is evolving as one of the promising techniques for the future generation of flat panel displays (FPD). Such FED applications are arranged from several "pixels", which are associated with several field emission cells (FECs), in the array order. The characteristics that affect the power of field emitter arrays include the shape and work function of emission materials, the distance between tip and gate, and the vacuum environmental condition. Diamond films (111) plane possess negative electron affinity (NEA) characteristics, in addition to the useful properties such as high electron mobility, high thermal conductivity, and chemical inertness. Therefore, this material is considered to be highly promising for applications in electron field emission devices and the related emission properties have been widely investigated. In this thesis, we successfully demonstrate the feasibility of the proposed scheme that a new process of gate structure MIS diode by using IC technology process, then deposition the diamond film in this MIS diode form a column-like diamond with gated FEAs by using bias assisted microwave plasma chemical vapor deposition (BAMPCVD) system. Moreover, we compare the gate structure and diamond tip morphology for the influence of field emission characterization, for instance the two different structure and morphology diamond FEAs. One is the column-like diamond FEAs with a 4 μm gate aperture and shallow depth of silicon substrate to gate (about 400nm), the other is the cone-shape diamond FEAs with a 8 μm gate aperture and deep depth of silicon substrate to gate (about 700nm). According to our results, the threshold voltage of column-like diamond FEAs and cone-shape diamond FEAs is about 10 V and 12V; the field emission current density is about 139 mA/cm2 (at Vgc=20V) and 98 mA/cm2 (at Vgc=50V) respectively. The electron field emission characteristics for the diamond field emitter array devices with different gate structure and tip morphology has a visible influence.