Trench gate NMOS transistor and trench gate PMOS transistor monolithically integrated in same semiconductor die

A method of fabricating a semiconductor die, the method comprising:

• forming a trench gate NMOS transistor in a first device region of a silicon substrate;
• forming a trench gate PMOS transistor in a second device region of the silicon substrate;
• forming an isolation structure between the first device region and the second device region;
• and
• electrically connecting the trench gate PMOS transistor to the trench gate NMOS transistor,
• wherein forming the trench gate PMOS transistor comprises:
• forming a p-type drift region in the second device region;
• forming a plurality of first stripe-shaped gate trenches that extend from a first main surface of the silicon substrate and terminate at a depth in the p-type drift region, each of the first stripe-shaped gate trenches having a first sidewall and a second sidewall opposite the first sidewall;
• forming a gate electrode in each of the first stripe-shaped gate trenches and dielectrically insulated from the silicon substrate by a gate dielectric;
• forming an n-type body region at the first sidewall of each of the first stripe-shaped gate trenches;
• forming a p-type source region above the n-type body region at the first sidewall of each of the first stripe-shaped gate trenches;
• and
• forming a p-type drain region closer to the second sidewall of each of the first stripe-shaped gate trenches than the first sidewall.

A semiconductor die, comprising:

• a silicon substrate;
• a trench gate NMOS transistor formed in a first device region of the silicon substrate;
• a trench gate PMOS transistor formed in a second device region of the silicon substrate and electrically connected to the trench gate NMOS transistor;
• and
• an isolation structure interposed between the first device region and the second device region,
• wherein the trench gate PMOS transistor and the trench gate NMOS transistor form a stage of a gate driver,
• wherein at least one additional stage of the gate driver is not integrated in the semiconductor die.