The invention discloses a method for preparing
a diamond base FET device with the T-similar-type grid shelter
autocollimation technology, and relates to the technical field of methods for manufacturing
semiconductor devices. The method comprises the step of forming a high-resisting
diamond layer on a high
temperature resistance substrate, the step of forming a
conducting channel in the high-resisting
diamond layer, the step of covering the surface of the high-resisting
diamond layer with a
metal mask layer, the step of photoetching a table-board, the step of removing a
metal mask outside the table-board area through corrosive liquid, the step of forming grids on the
metal mask in a photoetching mode, the step of removing the metal mask in the middle of a source leaking area through the corrosive liquid and forming source leakage, the step of manufacturing the T-similar-type grids in the
corrosion area, the step of oxidizing or
nitriding the outer sides of metal grids and forming a
dielectric layer, and the step of enabling the T-similar-type grids to serve as a shield. According to the method, the T-similar-type grid shelter
autocollimation technology is adopted, the distance between a grid source position and a grid leakage position is effectively shortened and is basically equal to the grid length, and the grid source resistance and grid leak resistance are reduced.