Memory device and method for fabricating the same
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsRainer Yen-Chieh Huang, Hai-Ching Chen, Chung-Te Lin
Life of this patent
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Abstract
An integrated circuit device includes a ferroelectric layer that is formed with chlorine-free precursors. This ferroelectric material may be of the composition HFxZr1-xO2. The ferroelectric layer may be used in a memory device such as a ferroelectric field effect transistor (FeFET). A ferroelectric layer formed with chlorine-free precursors has no chlorine residue. The absence of chlorine ameliorates time-dependent dielectric breakdown (TDDB) and Bias Temperature Instability (BTI).
Claims20
A method of forming an integrated circuit device, the method comprising:
- forming a ferroelectric layer by an atomic layer deposition (ALD process) using chlorine-free precursors, wherein the ferroelectric layer has a top surface that results from the ALD process and the chlorine-free precursors comprise a hafnium (Hf) compound and a zirconium (Zr) compound;
- prior to any further processing of the ferroelectric layer subsequent to the ALD process, depositing either a dielectric layer-metal oxide semiconductor layer stack, a metal oxide semiconductor layer, or a top electrode layer directly over and in contact with the top surface.
A method of forming an integrated circuit device, the method comprising:
- forming a bottom electrode layer in or on a substrate;
- forming a ferroelectric layer having a top surface directly over the bottom electrode layer by an atomic layer deposition process that includes repeating steps comprising:
- exposing the substrate to an evaporated zirconium (Zr) compound that is chlorine-free and forms a first surface layer;
- exposing the substrate to a first gas so that the first gas reacts with the first surface layer to form a zirconium-containing layer;
- exposing the substrate to an evaporated hafnium (Hf) compound that is chlorine-free and forms a second surface layer;
- exposing the substrate to the first gas so that the first gas reacts with the second surface layer to form a hafnium-containing layer;
- forming either a dielectric layer-metal oxide semiconductor layer stack, a metal oxide semiconductor layer, or a top electrode layer directly over and in contact with the top surface that is uppermost in the ferroelectric layer at the conclusion of the atomic layer deposition process.
A method of forming an integrated circuit device, the method comprising:
- forming a bottom electrode layer;
- forming by atomic layer deposition from chlorine-free gaseous metal precursors comprising a zirconium (Zr) precursor and a hafnium (Hf) precursor a ferroelectric layer with an upper surface directly over the bottom electrode layer;
- and
- immediately after the atomic layer deposition process, forming either a dielectric layer-metal oxide semiconductor layer stack, a metal oxide semiconductor layer, or a top electrode layer over and in direct contact with the upper surface, wherein the chlorine-free gaseous metal precursors are metals bonded with organic functional groups via oxygen, carbon, or nitrogen.
Dependencies are inferred from the claim text.