The invention belongs to the technical field of microprocessing, and relates to a
laser etching method of an MEMS
silicon structure. The
laser etching method comprises the following steps: a
laser beam conducts
local irradiation on the surface of a
silicon material through an objective lens, and the
silicon material absorbs part of energy and then is heated; the surface of an
irradiation area is molten into a molten area, part of the
molten silicon material is vaporized into a
smoke plume and molten splashes, and the molten part is scattered on the processed surface of the silicon material toform
solid splashes; and laser
irradiation is completed, the silicon material is condensed, and heat affected areas and cracks appear on the
irradiation area of the silicon material. Under the condition that the average power and pulse width of the laser beam are not changed, influences of recast
layers and
pollution of the surrounding splashes can be reduced by decreasing the repetition frequencyof a laser device and increasing single-time
pulse energy; through defocusing amount compensation, the maximum
local irradiation intensity and the minimum
etching diameter are obtained, and etching splashing is relieved; and through an auxiliary vacuum environment, dissipation in the laser transmitting process is reduced, the relatively-high irradiation intensity is obtained, and the heat affected areas are reduced.