DEVELOPMENT OF GATED TRANSITION METAL NITRIDE FIELD EMITTER ARRAYS

我们研制了一种门控氮化铌场发射极阵列。该工艺可分为两大工艺：氮化铌覆盖发射极的制备和栅极的制备。采用传递模技术制作氮化铌发射极，可以均匀地制作发射极顶点。将一组26个圆转移到表面氧化的硅衬底上。采用四甲基氢氧化铵各向异性蚀刻法进行了模具的成形。氧化后的模具在射极和栅极之间提供一层绝缘层，并通过以下工艺进行附着。去除硅模后，在绝缘层上沉积钼栅电极。采用蚀刻反法形成栅极孔径。将所制备的器件安装在真空室中，并在高真空条件下对其电子发射性能进行了评价。第一期驱动电压为14V，偶次放电后，驱动电压升至20V。除放电外，排放稳定。观察了发射模式，发现部分发射电子入射到栅电极上。通过对制备工艺的优化，进一步提高了材料的发射性能。

We have developed a gated niobium nitride field emitter arrays. The fabrication process can be divided into two major processes : fabrication of emitter covered with niobium nitride and fabrication of gate electrode. We adopted the transfer mold technique to fabricate niobium nitride emitter, by which we can fabricate the emitter apex uniformly. A set of 26 circles were transferred to silicon substrate of which surface had been oxidized. Formation of the mold was performed by anisotropic etching with tetramethylammoniumhydroxide. Oxidation of the mold provide an insulating layer between emitter and gate, which was attached by the following process. After removal of silicon mold, we deposited molybdenum gate electrode onto the insulating layer. Gate aperture was formed by etching back method. The fabricated device was installed into a vacuum chamber and was evaluated its electron emission performance in high vacuum. The driving voltage was 14V at the first stage and after occasional discharges, it increased to 20V.Emission was stable except discharges. Emission pattern was observed and we found some portion of the emitted electrons was incident on the gate electrode. Optimizing the fabrication process, we expect further improved emission property.