FeFET TRANSISTOR

A method of manufacturing a first transistor and a second transistor on a same semiconductor substrate, the method comprising:

• depositing an interface layer on the semiconductor substrate;
• depositing a gate insulator layer on the interface layer;
• depositing a protection layer on the gate insulator layer;
• opening the protection layer above a gate of the first transistor, the gate of the first transistor including at least a portion of the gate insulator layer;
• depositing a first ferroelectric layer on the protection layer and the gate of the first transistor;
• etching portions of the first ferroelectric layer on the protection layer, and etching the protection layer, to thereby form a first ferroelectric structure over the gate of the first transistor.

A method of manufacturing a first transistor and a second transistor on a semiconductor substrate, the method comprising:

• depositing a stack of layers on the semiconductor substrate, said stack comprising:
• an interface layer made of silicon oxynitride;
• a gate insulator layer;
• a first ferroelectric layer extending over the gate insulator layer at a first region for the first transistor;
• a metal gate layer extending over the gate insulator layer at a second region for the second transistor and further extending over the first ferroelectric layer at the first region for the first transistor;
• and
• patterning the stack of layers to form a first gate stack at the first region for the first transistor and form a second gate stack at the second region for the second transistor.