常关断型hemt晶体管以及对应的制造方法

The invention relates to an HEMT transistor of the normally off type and a corresponding manufacturing method. The HEMT transistor of the normally off type, including: a semiconductor heterostructure (4, 6, 200), which comprises at least one first layer (4) and one second layer (6), the second layer being set on top of the first layer; a trench (15), which extends through the second layer and a portion of the first layer; a gate region (10) of conductive material, which extends in the trench; and a dielectric region (18), which extends in the trench, coats the gate region, and contacts the semiconductor heterostructure. A part of the trench is delimited laterally by a lateral structure (LS) that forms at least one first step (Pb1, Pl1, Pb2). The semiconductor heterostructure forms a first edge (E1) and a second edge (E2) of the first step, the first edge being formed by the first layer.