Method of manufacturing semiconductor device
To allow a metal oxide film composed mainly of O and at least one of Hf and Zr to exhibit ferroelectric properties. After deposition of a hafnium oxide film on a semiconductor substrate via an insulating film, the semiconductor substrate is exposed to microwaves to selectively heat the hafnium oxide film. This makes it possible to form a larger number of orthorhombic crystals in the crystals of the hafnium oxide film. The hafnium oxide film thus obtained can therefore exhibit ferroelectric properties without adding, thereto, an impurity such as Si. This means that the hafnium oxide film having a reverse size effect can be used as a ferroelectric film of a ferroelectric memory cell and contributes to the manufacture of a miniaturized ferroelectric memory cell.
1. A method of manufacturing a semiconductor device including a field effect transistor and a capacitor, comprising:
forming the field effect transistor on a semiconductor substrate, the field effect transistor having a gate insulating film made of silicon oxide film;
after the forming of the field effect transistor, depositing an interlayer insulating film on the semiconductor substrate; and
after the depositing of the interlayer insulating film, forming the capacitor on the interlayer insulating film by:
(a) depositing a first conductor film over the interlayer insulating film;
(b) after the (a), depositing, over the first conductor film, a metal oxide film having oxygen and hafnium as a main component;
(c) after the (b), depositing a second conductor film over the metal oxide film;
(d) after the (c), subjecting the metal oxide film to microwave heat treatment; and
(e) after the (d), patterning the first conductor film, the metal oxide film and the second conductor film,
wherein the second conductor film is deposited by RF sputtering, and
wherein the field effect transistor and the capacitor configure a ferroelectric memory cell.
2. The method of manufacturing a semiconductor device according to claim 1 ,
wherein the second conductor film in the step (c) has TiN as a main component.
3. The method of manufacturing a semiconductor device according to claim 1 ,
wherein at least any one of elements Si, N, C and F is added to the metal oxide film.
4. The method of manufacturing a semiconductor device according to claim 1 ,
wherein the frequency of the microwaves in the step (d) is from 1 GHz to 10 GHz.
5. The method of manufacturing a semiconductor device according to claim 1 ,
wherein the metal oxide film is deposited at a temperature of less than 400° C.