Cascode transistor device and manufacturing method thereof

A manufacturing method of a semiconductor device, at least comprising the steps of:

• providing a substrate;
• forming a patterned conductive layer on the substrate, wherein the patterned conductive layer includes a first conductive region;
• electrically connecting a first transistor structure to the patterned conductive layer by flip-chip bonding, wherein the first transistor structure includes a first source, a first gate and a first drain;
• electrically connecting a second transistor structure to the patterned conductive layer by flip-chip bonding, wherein the second transistor structure includes a second source, a second gate and a second drain, and the first gate is electrically connected to the second source through the patterned conductive layer, and the first source is electrically connected to the second drain through the patterned conductive layer, and the first source and the second drain are both electrically connected to the first conductive region, and
• disposing a connection wire, wherein one end of said connection wire is directly physically contacting and electrically connected to the second drain, and another end of said connection wire is directly physically contacting and electrically connected to the first conductive region.