Effect of magnetron sputtering parameters and stress state of W film precursors on WSe2layer texture by rapid selenization.
Tungsten diselenide (WSe2) film was obtained by rapid selenization of magnetron sputtered tungsten (W) film. To prevent WSe2film peeling off from the substrate during selenization, the W film was designed with a double-layer structure. The first layer was deposited at a high sputtering-gas pressure to form a loose structure, which can act as a buffer layer to release stresses caused by WSe2growth. The second layer was deposited naturally on the first layer to react with selenium vapour in the next step. The effect of the W film deposition parameters(such as sputtering time, sputtering-gas pressure and substrate bias voltage)on the texture and surface morphology of the WSe2film was studied. Shortening the sputtering time, increasing the sputtering-gas pressure or decreasing the substrate bias voltage can help synthesize WSe2films with more platelets embedded vertically in the matrix. The stress state of the W film influences the WSe2film texture. Based on the stress state of the W film, a model for growth of the WSe2films with different textures was proposed. The insertion direction of the van der Waals gap is a key factor for the anisotropic formation of WSe2film.
State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China.|Chongyi Zhangyuan Tungsten Industry Corporation Limited, Ganzhou 341300, China.
Hongchao
H
Li
State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China.
Di
D
Gao
State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China.
Senlin
S
Xie
State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China.
Jianpeng
J
Zou