Power mosfet device having improved safe-operating area and on resistance, manufacturing process thereof and operating method thereof

A method for operating a power MOSFET device, the method comprising:

• biasing, in a first operating mode, an insulated-gate region at a first value of a gate voltage and at a value of a drain voltage correlated to a voltage applied between a drain region and source regions;
• operating a first device portion in a saturation region;
• generating a first value of a first current and a second device portion is in an inhibition state, the first value of the gate voltage being higher than a first threshold voltage and lower than a second threshold voltage;
• and
• biasing, in a second operating mode, the insulated-gate region at a second value of the gate voltage and at the value of the drain voltage;
• operating the first device portion in ohmic region;
• generating a second value of the first current;
• and
• operating the second device portion in ohmic region;
• and
• generating a value of a second current, the second value of the gate voltage being higher than the second threshold voltage,
• the first value of the first current is lower than a sum of the second value of the first current and of the value of the second current.

A method, comprising:

• forming a power MOSFET device;
• forming, a first body region and a second body region, the first body region having a first conductivity type, and the second body region having the first conductivity type;
• forming a drain region having a second conductivity type different from the first conductivity type in a portion of a semiconductor body under the first and the second body regions;
• forming in the first and the second body regions, a first source region and a second source region having the second conductivity type;
• and
• forming an insulated-gate region facing the first body region, the second body region, the first source region, the second source region and the drain region;
• forming a first channel region in the first body region between the first source region and the drain region;
• forming a second channel region the second body region between the second source region and the drain region.