鉑閘極結構化鑽石場發射陣列之製作與特性研究

Abstract

真空微電子技術應用在半導體用重要的電子元件，特別是場效平面顯示器，已引起許多研究者廣泛的注意。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pixel 依陣列方式規則排列而成。 利用高電場在FEC之尖端發射電子，而影響整個發射場功率的因素，包括發射材料之外型及其功函數、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）面具有負的電子親和力或非常小的電子親和力特性，使得鑽石成為最具潛力之固態電子元件的發射器材料。 在本實驗中，我們結合制作金屬╱絕緣體╱半導體（MIS）結構元件之IC製程技術及成長鑽石膜之偏壓輔助微波電槳化學氣相沈積技術，成功的製作出圓錐形鑽石場發射陣列元件。以鉑金屬層作為閘極，ITO玻璃為陽極，矽基材為陰極，閘極與陰極間以二氣化矽作為絕緣層，陽極與閘極間距離為10mm，形成一個三極場發射陣列元件。將此元件放入1×10-6Torr的高真空中，陰極上外加一高電壓1000V，閘極的電壓由0逐漸增加至50V，可求得場發射電流。結果顯示，場發射元件閘極之起始電壓約為12V，當閘極電壓增加至30V時，場發射電流約為40uA。同同時由F-N函數的線性關係亦可得知，此種鑽石陣列元件之電子場發射的起始電壓及其功函數等特性。 另外，我們也探討金中間層對化學氣相沈積鑽石薄膜之電子場發射的影響。實驗結果顯示，有鍍金之矽基材上沈積的鑽石膜之場發射電流密度為528uA/cm2，而無鍍金的場發射電流密度為32uA/cm2。因此，可以證實鍍金中間層的存在可有效的改善鑽石薄膜之場發射電流。

Vacuum-microelectronic technology has found extensive applications in semiconducting electric devices, particularly in field emission display (FED). Such FED applications are arranged from several "pixels", which are associated with several field emission cells (FECs), in the array order. Applying a high electric field on the field emitter array emits electrons from the tip of field emitter array (FEA). 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. However, (111) plane of diamond has a negative or very samll electron affinity. Therefore as widely recognized, the diamond is the promising material for use in manufacturing a solid-state electron emitter. In this experiment, we successfully fabricate cone- shaped diamond field emitter array devices by using two technologies. A metal - insulator-semiconductor (MIS) diode structure is initially made by applying IC process. Diamond film is then deposited on the field emitter array devices by using bias assisted microwave plasma chemical vapor deposition (BAMPCVD). Herein, Pt layer is used as the gate, ITO glass as the anode, the silicon substrate as the cathode, the SiO2 layer as the insulator between gate and cathode, form a triode field emission array device. The distance between the gate and anode is about 10 mm, and it is placed in the 1×10-6 Torr vacuum chamber. The field emission current is measured when applying +1000V voltage on the anode in which the applied gate voltage is varied from 0 to 50 volts. According to our results, the threshold voltage of this device is about 12 V and the field emission current is about 40 ua when the gate voltage is 30 V. The electron field emission characteristics of the diamond field emitter array devices that are threshold voltage and work function et.al. from Fowler-Nordheim plot with a linear relationship. Moreover, this study investigates the electron field emission properties. ALSo examined herein is how Au intermediate layer influences the electron field emission characteristics of CVD diamond films. Results presented herein demonstrate that the diamond film on the Si substrate with Auprecoating that filed emission current density is 528 ua/cm2, but without Au-precoating is 32 uA/cm2. So, the existence of Au-precoating intermediate layer can improve the electron field emission properties of diamond films.