HfO2,-based ferroelectric capacitor and preparation method thereof, and HfO2,-based ferroelectric memory

A preparation method of a HfO2-based ferroelectric capacitor, comprising the following steps:

• providing and cleaning a substrate layer;
• preparing a bottom electrode on the cleaned substrate layer by a sputtering process;
• depositing a dielectric layer on the bottom electrode;
• depositing an Al2O3 intercalation layer on the dielectric layer;
• applying a photoresist on the Al2O3 intercalation layer, exposing and developing;
• preparing a top electrode on the Al2O3 intercalation layer treated as above by a sputtering process;
• preparing a metal protective layer on the top electrode by a sputtering process;
• and removing the photoresist and excess metal, and annealing;
• wherein the dielectric layer is made of HZO, with a thickness of 8-15 nm, and a molar ratio of Hf to Zr being (0.4-0.6):(0.4-0.6);
• wherein the Al2O3 intercalation layer with a thermal expansion coefficient smaller than TiN is inserted between the dielectric layer and the top electrode (TiN) of the ferroelectric capacitor to provide larger tensile stress during annealing, thereby increasing the ratio of the o-phase component in the dielectric layer to achieve the purpose of increasing the remanent polarization and increase the memory window of the ferroelectric memory, thereby effectively preventing misreading of data and improving the reliability of the memory;
• wherein the metal protective layer is made of one of Pd, Au and Pt;
• and
• wherein the annealing is performed at 400-500° C. in N2 for 20-30 s.

A HfO2-based ferroelectric memory, comprising

• a HfO2-based ferroelectric capacitor,
• the HfO2-based ferroelectric capacitor comprises a substrate layer, a bottom electrode, a dielectric layer, an Al2O3 intercalation layer, a top electrode and a metal protective layer in sequence from bottom to top;
• wherein the dielectric layer is made of HZO, with a thickness of 8-15 nm, and a molar ratio of Hf to Zr being (0.4-0.6):(0.4-0.6);
• wherein the Al2O3 intercalation layer with a thermal expansion coefficient smaller than TiN is inserted between the dielectric layer and the top electrode (TiN) of the ferroelectric capacitor to provide larger tensile stress during annealing, thereby increasing the ratio of the o-phase component in the dielectric layer to achieve the purpose of increasing the remanent polarization and increase the memory window of the ferroelectric memory, thereby effectively preventing misreading of data and improving the reliability of the memory;
• wherein the metal protective layer is made of one of Pd, Au and Pt;
• wherein the annealing is performed at 400-500° C. in N2 for 20-30 s.