Patent ID: 11949400
Assignee: RF360 SINGAPORE PTE. LTD.
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A layer system comprising:
a monocrystalline sapphire substrate having a first surface;
a crystalline piezoelectric layer comprising an aluminum nitride (AlN), grown epitaxially on the first surface, and having a second surface facing away from the first surface;
wherein the first surface is a crystallographic R-plane of sapphire;
wherein the epitaxial relationship between the monocrystalline sapphire substrate and the crystalline piezoelectric layer is as follows:
a (11-20)-plane of the crystalline piezoelectric layer (x-cut) is parallel to a (1-102)-plane of the monocrystalline sapphire substrate (R-plane),
an in-plane [1-100]-direction of the crystalline piezoelectric layer is parallel to a [−1-120]-direction of the monocrystalline sapphire substrate, and
an in-plane [000-1]-direction (crystallographic c-axis) of the crystalline piezoelectric layer is parallel to a [1-10-1]-direction of the monocrystalline sapphire substrate.