The present invention addresses the problem of providing a novel technology for measuring an etching amount in heat treatment in which growth and etching proceed simultaneously. The present invention includes: a first substrate thickness measuring step S10 for measuring the thickness 10D of a to-be-heat-treated semiconductor substrate 10; a second substrate thickness measuring step S20 for measuring the thickness 20D of a heat-treated semiconductor substrate 20; a growth layer thickness measuring step S30 for measuring the thickness 21D of a growth layer 21 which has gone through crystal growth by heat treatment; and an etching amount calculating step S40 for calculating the etching amount ED on the basis of the thickness 10D of the to-be-heat-treated semiconductor substrate 10, the thickness 20D of the heat-treated semiconductor substrate 20, and the thickness 21D of the growth layer 21.

An optical filter including at least one of a high refractive index material and a low refractive index material; wherein the optical filter exhibits a reduced angle shift in at least one of a visible, near infrared, and an extreme ultraviolet wavelength is disclosed. A method of depositing a film is also disclosed.

The present disclosure relates to an optical sensing module, a system and a method for operating the optical sensing system. The optical sensing module includes a light emitter that emits a sensing light in a specific wavelength range and a photodiode unit. The photodiode unit includes a first photodiode used to sense a first wavelength light, a second photodiode used to sense a second wavelength light, and a third photodiode used to sense a third wavelength light. The optical sensing module implements a proximity sensor by operations of the second photodiode and the third photodiode, or a biometric sensor by operations of the first photodiode, the second photodiode, and the third photodiode. The photodiode unit receives a reflected light from an object to be detected so as to determine if the object is proximal, and then determine whether or not the proximal object is human skin.