Method for the formation of a thin optical crystal layer overlying a low dielectric constant substrate

Abstract

A method for the formation of a thin optical crystal layer (e.g., a thin LiNbO optical single crystal layer) overlying a low dielectric constant substrate (e.g., a low dielectric constant glass substrate). The method includes implanting ions (e.g., He ) through a surface of an optical crystal substrate. The implanting of the ions defines, in the optical crystal substrate, a thin ion-implanted optical crystal layer overlying a bulk optical crystal substrate. A low dielectric constant substrate is subsequently bonded to the surface, using either a direct or an indirect bonding technique, to form a bonded structure. The bonded structure is thermally annealed at a temperature in the range of 300° C. to 600° C. for 30 minutes to 300 minutes. Thereafter, the thin ion-implanted optical crystal layer and low dielectric constant substrate are separated from the bulk optical crystal substrate using mechanical force applied to the low dielectric constant substrate and/or the bulk optical crystal substrate in the direction of separation. As a result, a thin optical crystal layer overlying a low dielectric constant substrate is formed. The thin optical crystal layer has characteristics (e.g., an electro-optical coefficient, surface quality and homogeneity) that are equivalent to the optical crystal substrate, from which it originated, and is thus suitable for use in electro-optical devices. Furthermore, the low dielectric constant substrate enables the manufacturing of electro-optical devices with a reduced RF and optical wave velocity mismatch, a broad bandwidth and a low modulation or switching voltage.