2results about How to "Good crystallinity" patented technology

The problem to be solved by the present invention is to provide a novel technique for manufacturing large-diameter AlN substrates. The present invention relates to a method for manufacturing an AlN substrate, including a crystal growth step (S30) of forming an AlN layer (20) on a SiC substrate (10) having through-holes (11). Furthermore, the present invention also relates to a method for forming the AlN layer (20), including a through-hole forming step (S10) of forming through-holes (11) on the SiC substrate (10) before forming the AlN layer (20) on the surface of the SiC substrate (10).

A polyvinyl alcohol (PVA) film is provided that exhibits low leaching of PVA-based resin into water during polarization film manufacturing, suppressed contamination of the chemical bath during manufacturing, high productivity with few foreign defects, and excellent stretch processability during manufacturing. A PVA-based film is provided in which, on both surfaces of the PVA-based film, a region extending from the surface layer of each film surface to a depth of 1 μm satisfies the following formula (1), and the weight swelling degree is 185% or more and 210% or less. |K| ≥ 3.5 × 10 ‑5 ……(1). (Here, |K| is the absolute value of the ratio (slope) of the change in the magnitude of birefringence from the surface to a depth of 1μm.)