The preparation method comprises the following steps: taking
silicon as a substrate layer, growing Si3N4
passivation layers on the upper surface and the lower surface of the
silicon substrate by adopting a
chemical vapor deposition technology, spin-
coating a negative
photoresist layer on the Si3N4
passivation layer on one surface by utilizing a spin coater, exposing and developing the negative
photoresist layer, and repeating the steps on the other surface, thereby obtaining the
radiation-resistant ultrafast response
silicon detector. Hole patterns formed after photoetching of the front face and the back face are mutually nested,
photoresist is washed away through photoresist removing liquid after the exposed part of the Si3N4
passivation layer is removed, then the silicon substrate is soaked in
etching liquid to be subjected to constant-temperature and ultrasonic treatment, the silicon substrate is etched to form a three-dimensional hole structure, the residual Si3N4 passivation layer on the surface is removed, and the three-dimensional hole structure is obtained. And finally depositing
metal electrodes on the front and back surfaces of the sample respectively. According to the three-dimensional rhombic hole structure provided by the invention, the
radiation resistance and ultrafast response capability of the
silicon detector can be effectively improved, the selective wet
etching quality is high, and the
etching cost is low.