METHOD OF DEPOSITING AMORPHOUS FILM ON CAPACITOR ASSEMBLY
A capacitor assembly includes a semiconductor substrate having an interlayer insulation film on a first main surface of the semiconductor substrate, and a conductive barrier layer formed on the interlayer insulation film. The capacitor assembly also includes a contact plug electrically connected to the conductive barrier layer through the interlayer insulation film, and a lower electrode formed on the barrier layer. The capacitor assembly also includes a capacitor insulation film formed on the lower electrode, and an upper electrode formed on the capacitor insulation film. The capacitor insulation film is made from a ferroelectric material. The barrier layer is an amorphous film which includes titanium and aluminum.
1 . A method of depositing an amorphous film on a plate by sputtering in a vacuum chamber, the amorphous film containing titanium, aluminum and nitrogen, wherein nitrogen is an optional component, TiAl is used as a sputtering target, an inert gas in the vacuum chamber contains a N 2 —Ar mixture gas, and the sputtering is carried out under the following conditions:
A) a DC power supply during the sputtering is between 0.5 kW and 10 kW,
B) an inner pressure of the vacuum chamber is between 3 mTorr and 15 mTorr,
C) a temperature of the plate is between 100 degrees Celsius and 300 degrees Celsius, and
D) a volume ratio of N 2 gas in the N 2 —Ar mixture gas is between 0% and 70%.
2 . The method according to claim 1 , wherein the DC power supply during the sputtering is between 1 kW and 3 kW.
3 . The method according to claim 1 , wherein the inner pressure of the vacuum chamber is between 6 mTorr and 12 mTorr.
4 . The method according to claim 1 , wherein an electrical resistance of the amorphous film is 6×10 2 μΩcm or less.
5 . The method according to claim 1 , wherein the plate is a semiconductor substrate.
6 . The method according to claim 1 , wherein the amorphous film is a TiAl film or a TiAlN film.
7 . The method according to claim 1 , wherein the amorphous film is used as a conductive barrier layer of a product including the plate.
8 . The method according to claim 1 , wherein the amorphous film prevents oxygen penetration therethrough.
9 . The method according to claim 1 , wherein the amorphous film has a thickness of between about 20 nm and about 150 nm.