Silicon tip arrays with nanocomposite film for electron field emission applications

An array of field emitting tips made on silicon with coating nanocomposite film was made by a laser direct-write process. The laser was used in air: a single laser pulses forms a single conical tip and moved to create an array. In this process, the silicon substrate (n-Si) is heated locally above its melting point by a pulse YAG:Nd3+ laser. At the working pressure (∼105 Pa), most of the Si particles are deposited back on the target and on to the tip. As a result, the conical surface had many protuberances, all covered with the nanocomposite film. This film consists of nanocrystalline silicon in an SiOxNy matrix. Several samples were stain etched, and porous silicon (PS) layers were formed on the conical surface. These PS layers form the composite structure that contains nanocrystalline silicon in a porous SiOxNyHz matrix. –Nordheim current–voltage characteristics were usually observed. Relatively high emission parameters: effective emission areas α=10−8 cm2, local field enhancement factors β=105 cm−1 have been obtained. A resonant tunneling phenomenon has been found on some samples. The resonant peaks have been observed. Due to the quantum-size effect, there are some energy levels in the quantum well region that cause an increased tunneling probability under certain values of the electric field.