Control of hydrogen content in the carbon nitride materials and its development to the field emission devices based on the high-resolution laser spectroscopy

本研究旨在通过控制氢原子量来优化氢化非晶态碳氮化物(a-CNx：H)的场发射性能。含有微不足道的氢原子的氮化碳具有机械硬度的特性。另一方面，包括氢原子在内的那些原子通常是机械软的：当氢原子以NH或OH基团的形式包括时，它们具有良好的电场发射特性。特别是，由a-CN_x：H或a-CN_x：O：H薄膜包覆的导电Al掺杂的氧化锌单晶晶须(图1)组成的杂化材料具有FED器件的可能性。此外，含有CHn(n=1-3)基团的a-CN_x：H材料具有储氢特性。因此，控制a-CN_x：H或a-CN_x：O：H材料中的氢气量是合成具有物理p-…的材料的关键技术在本研究中，采用等离子体增强化学气相沉积工艺，利用稀有气体的微波或ECR等离子体分解氰化物(如BrCN和CH3CN)来合成氮化碳。2004年，本文进行了以下研究。(1)利用激光诱导荧光(LIF)光谱和静电探针法研究了Ar的微波放电产物对BrCN的分解过程以及前体CN自由基的形成和猝灭过程。BrCN的主要分解过程是Ar^的电荷转移，其次是BrCN^-e^-复合。CN自由基的主要猝灭过程是与未反应的BrCN反应。(2)由CN自由基的激光诱导荧光光谱、流速和沉积的a-CN_x：H膜的重量确定了CN自由基在a-CN_x：H膜上的附着几率(S)。S的数值在0.032-0.019托尔范围内与Ar气压呈负相关。S的这种负压依赖性可以用薄膜表面CN自由基的反应性来解释。(3)用He和BrCN混合气体的ECR等离子体CVD可以有效地合成氢气含量可控的a-CN_x：O：H。较少

The present study aims to optimize the electric-field-emission property of hydrogenated amorphous carbon nitrides (a-CN_x : H) by controlling the quantity of the hydrogen atoms contained. Carbon nitrides including negligible amount of hydrogen atoms have a property of mechanical hardness. On the other hand, those include hydrogen atoms are, in general, mechanically soft : they have excellent electric-field emission characteristic when the hydrogen atoms are included in the forms of the NH or OH groups. In particular, the hybridized material which consists of the electrically-conducting Al-doped ZnO single-crystal whiskers (Fig.1) coated by the a-CN_x : H or a-CN_x : O : H thin films has a possibility of the FED device. In addition, a-CN_x : H materials containing CH_n(n=1-3) groups have the hydrogen-storage characteristic. Therefore, the control of the hydrogen quantity in the a-CN_x : H or a-CN_x : O : H materials is the key technology to synthesize the materials having the physical p … More roperties hoped.In the present study, carbon nitrides are synthesized by using the plasma enhanced CVD processes by applying the decomposition of cyanides such as BrCN and CH_3CN with the microwave or ECR plasmas of rare gases. In 2004, following studies are made. (1)The decomposition process of BrCN by the microwave-discharged products of Ar and the formation and quenching processes of the precursor CN radicals were investigated based on the laser-induced fluorescence (LIF) spectroscopy and the electrostatic-probe method. The dominant process of decomposition of BrCN is the charge transfer from Ar^+ followed by the BrCN^+-e^-recombination. The dominant quenching process of CN radicals is the reaction with unreacted BrCN. (2)The sticking probability (s) of the CN radicals onto the a-CN_x : H film was determined from the LIF spectroscopy of CN radicals, flow speed, and the weight of the a-CN_x : H film deposited. The s value is in the range of 0.032-0.019 being negatively dependent on the pressure of Ar in the range of 0.3-0.7 Torr. This negative pressure dependence of s can be explained by the reactivity of the CN radicals on the film surface. (3)ECR plasma CVD of the mixed gases of He and BrCN was found to be effective for the synthesis of a-CN_x : O : H with the hydrogen amount in a controlled fashion. Less