Thin film transistors having ferroelectric material for providing pixel compensation

A manufacturing method of an active device substrate, comprising:

• forming a first semiconductor layer and a second semiconductor layer above a substrate;
• forming a gate dielectric layer on the first semiconductor layer, wherein the gate dielectric layer has an opening;
• forming a ferroelectric material layer on the gate dielectric layer and the second semiconductor layer;
• forming a first gate and a second gate on the ferroelectric material layer, wherein a gate dielectric structure is sandwiched between the first gate and the first semiconductor layer, wherein the gate dielectric structure comprises a stack of a portion of the gate dielectric layer and a portion of the ferroelectric material layer, wherein another portion of the ferroelectric material layer is sandwiched between the second gate and the second semiconductor layer, and the another portion of the ferroelectric material layer is filled into the opening of the gate dielectric layer;
• forming a first source and a first drain electrically connected to the first semiconductor layer;
• and
• forming a second source and a second drain electrically connected to the second semiconductor layer, wherein a first semiconductor device comprises the first gate, the first semiconductor layer, the gate dielectric structure, the first source and the first drain, and a second semiconductor device is electrically connected to the first semiconductor device and comprises the second gate, the second semiconductor layer, the another portion of the ferroelectric material layer, the second source and the second drain.