Tuning the Piezoelectric Coefficient of a Doped Piezoelectric Material Using Multiple Noble Gases
A process chamber is provided. A target comprising an alloy comprising a base metal atomic species and an alloy atomic species is placed in the process chamber. The concentration of the alloy atomic species is subject to a manufacturing variation. A substrate is placed in the process chamber. While supplying gases comprising a noble gas of a first atomic species and a noble gas of a second atomic species, different from the first atomic species, to the process chamber, a sputtering operation is performed to transfer target material from the target to the substrate to form a piezoelectric film. A relative flow rate is set between the noble gas of the first atomic species and the noble gas of the second atomic species to form the film with a predetermined piezoelectric coefficient notwithstanding the manufacturing variation.
1 . A method of sputter depositing a doped aluminum nitride film on a substrate, the method comprising:
providing a process chamber;
placing a target in the process chamber, the target comprising an alloy comprising aluminum and an alloy atomic species, the alloy atomic species having a concentration in the alloy subject to a manufacturing variation;
placing the substrate in the process chamber; and
while supplying nitrogen, a noble gas of a first atomic species and a noble gas of a second atomic species, different from the first atomic species, to the process chamber, performing a sputtering operation to transfer target material from the target to the substrate to form the film; and
setting a relative flow rate between the noble gas of the first atomic species and the noble gas of the second atomic species to form the film with a pre-defined piezoelectric coefficient notwithstanding the manufacturing variation in the concentration of the alloy atomic species in the alloy.
2 . The method of claim 1 , in which the performing comprises performing one of pulsed DC sputtering and RF sputtering.
3 . The method of claim 1 , in which the noble gas of the first atomic species is argon.
4 . The method of claim 3 , in which the noble gas of the second atomic species is one of neon, krypton, and xenon.
5 . The method of claim 1 , in which the noble gas of the first atomic species is krypton.
6 . The method of claim 5 , in which the noble gas of the second atomic species is one of neon, argon, and xenon.
7 . The method of claim 1 , in which:
the method additionally comprises generating calibration data for the target; and
the setting comprises setting the relative flow rate in accordance with the calibration data.
8 . The method of claim 7 , in which the generating comprises measuring a concentration of the alloy atomic species in the target to generate at least part of the calibration data.
9 . The method of claim 7 , in which the generating comprises:
using the target to deposit at least one test film of doped aluminum nitride with a respective defined relative flow rate between the noble gas of the first atomic species and the noble gas of the second atomic species; and
measuring a piezoelectric coefficient of the at least one test film to generate at least part of the calibration data.
10 . A method of sputter depositing a doped piezoelectric film on a substrate, the method comprising:
providing a process chamber;
placing a target in the process chamber, the target comprising an alloy comprising a base metal atomic species and an alloy atomic species, in which a concentration of the alloy atomic species in the alloy is subject to a manufacturing variation;
placing the substrate in the process chamber;
while supplying gases comprising a noble gas of a first atomic species and a noble gas of a second atomic species, different from the first atomic species, to the process chamber, performing a sputtering operation to transfer target material from the target to the substrate to form the film; and
setting a relative flow rate between the noble gas of the first atomic species and the noble gas of the second atomic species to form the film with a predetermined piezoelectric coefficient notwithstanding the manufacturing variation in the concentration of the alloy atomic species in the alloy.
11 . The method of claim 10 , in which the performing comprises performing one of pulsed DC sputtering and RF sputtering.
12 . The method of claim 10 , in which the noble gas of the first atomic species is argon.
13 . The method of claim 12 , in which the noble gas of the second atomic species is one of neon, krypton, and xenon.
14 . The method of claim 10 , in which the noble gas of the first atomic species is krypton.
15 . The method of claim 14 , in which the noble gas of the second atomic species is one of neon, argon, and xenon.
16 . The method of claim 10 , in which:
the method additionally comprises generating calibration data for the target; and
the setting comprises setting the relative flow rate in accordance with the calibration data.
17 . The method of claim 16 , in which the generating comprises measuring a concentration of an alloy atomic species in the target to generate at least part of the calibration data.
18 . The method of claim 16 , in which the generating comprises:
using the target to deposit at least one test film of doped piezoelectric material with a respective defined relative flow rate between the noble gas of the first atomic species and the noble gas of the second atomic species; and
measuring a piezoelectric coefficient of the at least one test film to generate at least part of the calibration data.
19 . The method of claim 10 , in which the base metal atomic species is aluminum and the alloy atomic species is scandium.
20 . The method of claim 10 , in which the base metal atomic species is zinc and the alloy atomic species is magnesium.
21 . An electronic device, comprising a piezoelectric film comprising interstitial noble gas of two or more different atomic species.