Stripping method of thin-film material

Abstract

A technical process for manufacturing a monocrystal lithium niobate thin film or a monocrystal lithium tantalate thin-film material. After bonding of wafers, reduction of crystal lattice intensity of a damage layer caused by ion implantation and differences of thermal expansion coefficients between a silicon dioxide layer and a lithium niobate (lithium tantalate) crystal are utilized to select an appropriate heat treatment process and form stress in wafer set, so as to strip the film. The process can substantially reduce ion implantation dosage, thereby reducing production cost and increasing film quality.

Description

technical field [0001] The invention relates to a process for making single crystal lithium niobate thin film or single crystal lithium tantalate thin film material. Background technique [0002] Single crystal lithium niobate thin film or single crystal lithium tantalate thin film material with high refractive index difference has a very wide application prospect in integrated optics, optoelectronic components and nonlinear optics. Documents 1 and 2 respectively reported the methods of fabricating lithium niobate single crystal thin film and lithium tantalate single crystal thin film. The basic steps include ion implantation, silicon dioxide deposition and polishing, sample cleaning, direct bonding, heat treatment separation, thin film Polishing and other processes. The basic manufacturing principle can be explained by the process introduced in Document 3: (hydrogen or helium) ion implantation is performed on lithium niobate wafer or lithium tantalate wafer. After the ions...

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Problems solved by technology

Therefore, in Documents 1 and 2, the dose of ion implantation is relatively large (4×10 16 ions / cm 2 above) to ensure that there are enough ions to generate high-density bubbles, but the large-dose ion implantation has brought two disadvantages. One is that the implantation time is long, and the corresponding production cost is high. The second is the large-dose ion implantation. It will damage the crystal structure of the film and deteriorate the physical properties of the film

For example, in Document 4, a large dose of helium ion implantation caused the nonlinear optical coefficient of the lithium niobate thin film to be reduced to about half of that of the bulk material.

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