Passivation contact structure with selective tunneling layer thickness and preparation method and application thereof

The invention discloses a passivation contact structure with a selective tunneling layer thickness and a preparation method and application thereof. During preparation, a first tunneling silicon oxide layer is deposited on the back surface of a silicon substrate and covered with a compact cover plate with a gap structure, and the gap structure corresponds to a non-metal contact area; the part except the gap structure corresponds to the metal contact area; then depositing a second tunneling silicon oxide layer, wherein the gap structure can allow the second tunneling silicon oxide layer to be deposited in the non-metal contact region; removing the compact cover plate, depositing an amorphous silicon layer, and carrying out annealing treatment to form a phosphorus-doped polycrystalline silicon layer; according to the passivation contact structure manufactured through the method, a thin tunneling oxide layer structure is achieved in the metal contact area, a thick tunneling oxide layer structure obtained through