DLC-coated Si-tip FEA 제조에 있어서 기판 상에 경사-회전 증착된 Al 희생층을 이용한 Gate누설 전류의 감소

Decrease of Gate Leakage Current by Employing Al Sacrificial Layer Deposited on a Tilted and Rotated Substrate in the DLC-coated Si-tip FEA Fabrication

Lift-off를 이용한 DLC-coated Si-tip FEA 제조에 있어서 gate 절연막의 측면에 DLC가 coating되는 것을 방지하기 위해 기판 상에 Al 희생층을 경사-회전 증착한 뒤 DLC를 coating하고, 다음으로 희생층을 식각하여 tip 이외의 DLC를 제거하는 방법을 제안하였다. 이러한 Al희생층을 이용한 lift-off공정에 의해 제조된 DLC-coated Si-tip FEA의 전류전압 특성과 전류 표동 특성을 조사하였으며, gate 누설 전류의 감소와 방출 전류의 안정성을 확인하였다.

For the DLC-coaled Si-tip FEA, the modified lift off-process, by which DLC coated on both gate electrode surface and gate insulator in the gate aperture could be removed, was proposed. In the process, the Al sacrificial layer was deposited on a tilted and rotated substrate by an e-beam evaporation, and DLC film was coated on the substrate by PA-CVD method. Afterward the DLC was perfectly removed except the DLC films coated on emitter tips by etch-out of Al sacrificial layer. Current-voltage curves and current fluctuation of the DLC-coated Si-tip FEA showed that the proposed lift-off process played an important role in decreasing gate leakage current and stabilizing omission current.