The invention relates to a forming method of a
transistor. The forming method of the
transistor includes the following steps that: a
semiconductor substrate is provided, wherein the
semiconductor substrate includes a first region and a second region; a dummy
gate dielectric material layer is formed on the surface of the
semiconductor substrate, wherein the dummy
gate dielectric material layer includes a first insulating material layer and a second insulating material layer; a dummy gate and a second gate are formed; the dummy
gate dielectric material layer is etched with the dummy gate and the second gate adopted as a
mask, so that a dummy gate
dielectric layer and a second gate
dielectric layer are formed; first source / drain areas are formed in the first region, and
second source / drain areas are formed in the second region; a
dielectric layer is formed on the surface of the semiconductor substrate, and the surface of the
dielectric layer is flush with the surface of the dummy gate; and the second insulating material layer in the dummy gate dielectric material layer is removed through adopting a
dry etching process, and the first insulating material layer in the dummy gate dielectric material layer is removed through adopting a wet
etching process, and therefore, a groove can be formed; and a first gate structure is formed in the groove. With the forming method of the
transistor adopted, steps can be decreased, and the performance of the transistor can be improved.