掺杂浓度对硅锥阴极特性的影响

The influences of doping on the emission characteristic of a silicon emitter

基于漂移 扩散模型和量子理论中的WKB方法 ,用数值模拟方法分析了材料掺杂浓度对硅锥阴极场致发射特性及工作状态的影响 ,结果表明 ,硅锥阴极单纯的场致发射Iemit E特性受硅材料掺杂浓度的影响很小 .但低掺杂硅锥阴极顶端的电位随发射电流增大而明显上升 .锥体上电位变化可以等效为一个与锥体形状与掺杂相关的串联电阻的作用 ,这一电阻对单尖发射电流有负反馈作用 .另外 ,在常规的工作状态下 ,硅锥阴级的温升并不严重 .这些结果可以作为硅锥阴极设计的参考 .

A numerical method based on the Drift-Diffusion model and WKB approach was employed to analyze the influences of doping on the characteristic of a silicon emitter.The results show that there is little difference among the I emit-E characteristics for different-doped silicon emitters,while the apex potential of a lightly doped emitter increases with the emission current.The potential changes can be attributed to a result of a serial resistance when emission current is passing through it.This resistance,which is concerned with the doping and shape of the emitter,has a negative feedback action to the emission current of the emitter.Also,there is no serious temperature rising in the silicon emitter under the normal operating states.The conclusions here can be used as references for emitter design.