Method of depositing a layer
View Patent ↗This invention relates to a method of depositing a layer on an exposed surface of an insulating layer of material. The method includes treating the exposed surface with hydrogen or a gaseous source of hydrogen in the presence of a plasma, prior to or during deposition of a metallic layer.
1. A method of depositing an aluminum nitride layer on an exposed surface of previously deposited insulating layer on a substrate, said method comprising:
treating the exposed surface with hydrogen or a gaseous source of hydrogen in the presence of a plasma; and
depositing the aluminum nitride layer over the exposed surface,
wherein the hydrogen treatment occurs prior to or during the deposition of the aluminum nitride layer, wherein the plasma is supplied by a Reactive Ion Etching process, and wherein the aluminum nitride layer is deposited as a piezoelectric layer of an acoustic wave device.
2. The method as claimed in claim 1 wherein the hydrogen treatment time is less than 15 minutes.
3. A method of depositing an aluminum nitride layer on an exposed surface of previously deposited insulating layer on a substrate, said method comprising:
treating the exposed surface with hydrogen or a gaseous source of hydrogen in the presence of a plasma; and
depositing the aluminum nitride layer over the exposed surface,
wherein the hydrogen treatment occurs prior to or during the deposition of the aluminum nitride layer, and wherein a duration and plasma power of the hydrogen treatment are sufficient to improve the crystal orientation of the deposited aluminum nitride layer such that the x-ray diffraction peak half width on a crystallographic plane of the deposited aluminum nitride layer is narrowed relative to the x-ray diffraction peak half width on the crystallographic plane of an aluminum nitride layer deposited in the absence of the hydrogen treatment.
4. The method as claimed in claim 3 wherein the plasma is an Inductively Coupled Plasma.
5. The method as claimed in claim 4 wherein the substrate is placed on an RF biased platen.
6. The method as claimed in claim 5 wherein the platen is heated.
7. The method as claimed in claim 3 wherein the aluminum nitride layer is deposited as a piezoelectric layer of an acoustic wave device.
8. The method of treating an aluminum nitride layer including subjecting the aluminum nitride layer to atomic hydrogen so as to enhance the <111> crystallographic orientation of a conductive layer deposited on the aluminum nitride layer relative to the <111> crystallographic orientation of a conductive layer deposited on an aluminum nitride layer which has not been subjected to atomic hydrogen.
9. The method as claimed in claim 8 wherein the aluminum nitride layer is deposited as a piezoelectric layer of an acoustic wave device.
10. The method as claimed in claim 8 further including simultaneously subjecting the aluminum nitride layer to hydrogen plasma and depositing the conductive layer by metallic sputtering.