The invention discloses a side wall
etching method for reducing
heat current carrier injection damage.
Ion injection is carried out on a side wall deposition layer by using neutral ions, and the
ion injection direction forms an included angle with the direction vertical to a substrate and is inclined towards the source
electrode direction, so the
etching speed on the side wall above a source
electrode region is higher than the
etching speed on the side wall above a drain
electrode region in the side wall etching process, after etching, the cross section width of the side wall of a source electrode is relatively reduced, and the cross section width of the side wall of a drain electrode is relatively increased. After
voltage is applied on a grid electrode, the intensity of a longitudinal
electric field generated at the drain terminal is weakened, so
electron hole pairs are generated through the collision of current carriers accelerated by a transverse
electric field, and the injection into the grid electrode can be realized by holes under the effect of the weak longitudinal
electric field, so the grid current formed because of the hot current carrier injection is reduced, and the hot current carrier injection damage of a
semiconductor device is reduced.