Method and apparatus for measuring optical constants of a thin film as well as method and apparatus for fabricating a thin film utilizing same

A method for measuring optical constants of a thin film comprising:

• a step of disposing a first prism, a second prism and a third prism, the bottom surface of each of which is closely disposed to the thin film;
• a step of projecting a light beam coming from a light source through said first prism into said thin film;
• taking out light, which has been projected through said first prism into said thin film and which has propagated therein, to the exterior by means of said third prism to measure the intensity of the light;
• a step of taking out light, which has been projected through said first prism into said thin film and which propagated therein, to the exterior by means of said second prism to measure the intensity of the light;
• a step of taking out light, which has been reflected by the interface of said thin film, when light, which has propagated in said thir film, is taken out to the exterior by means of said second prism, and has propagated further therein, to the exterior by means of said third prism to measure the intensity of the light;
• a step of moving said second prism to a position, which is different from that used in the preceding step and taking out light, which has been projected through said first prism into said thin film and which has propagated therein, to the exterior by means of said second prism, which has been thus moved, to measure the intensity of the light;
• a step of taking out light, which has been reflected by the interface of said thin film, when light, which has propagated in said thir film, is taken out to the exterior by means of said second prism thus moved, and has propagated further therein, to the exterior by means of said third prism to measure the intensity of the light;
• and
• a step of calculating the propagation loss of the light propagating in said thin film by using measured values of said intensity of the light.

An apparatus for measuring optical constants of a thin film comprising:

• at lest one light source;
• a prism including a spherical surface disposed closely to the thin film, which makes at least one light beam coming from said at least one light source propagate in the medium thereof to project it through the spherical surface of said prism disposed closely to said thin film, to said thin film and makes light reflected by the spherical surface of said prism emerge to the exterior of said prism;
• a light receiving device integrally formed with said prism, for measuring the intensity of light reflected by the spherical surface of said prism;
• holding and driving means for holding said thin film and said prism and varies the relative position between said thin film and said light source;
• and,
• calculating control means for controlling said holding and driving means and calculating the optical constants of said thin films on the basis of measured values obtained by said light receiving device.

An apparatus for measuring optical constants of a thin film comprising:

• at least one light source;
• a prism disposed closely to the thin film, which makes at least one light beam coming from said at least one light source propagate in a medium thereof project it through a bottom surface of said prism disposed closely to said thin film, and makes light reflected by the bottom surface of said prism emerge to the exterior of said prism, a radius of curvature of the surface of said prism, which is closely disposed to said thin film, is comprised between 150 and 400 mm;
• a light receiving device for measuring the intensity of light reflected by the bottom surface of said prism;
• holding and driving means which holds said thin film and said prism and varies the relative position between said thin film and said light source;
• and
• calculating control means, which controls said holding and driving means and calculates the spherical constants of said thin films on the basis of measured values obtained by said light receiving device.

An apparatus for measuring optical constants of a thin film comprising:

• at least one light source;
• a first prism disposed closely to the thin film, which makes at least one light beam coming from said at least one light source propagate in a medium thereof to project it through a bottom surface of said first prism disposed closely to said tin film, and makes light reflected by a bottom surface of said first prism emerge to the exterior of said first prism;
• a light receiving device for measuring the intensity of light reflected by the bottom surface of said first prism;
• holding and driving means which holds said thin film and said first prism and varies the relative position between said thin film and said light source,
• calculating control means, which controls said holding and driving means and calculates the optical constants of said thin films on the basis of measured values obtained by said light receiving device;
• a second prism, which is movable, for taking out light, which has been projected by said first prism to said thin film and has propagated therein, to the exterior of said thin film;
• a second light receiving device for measuring light emerging from said second prism;
• and
• a monitoring third prism spaced from said first and second prism for taking out light, which has propagated in said thin film, to the exterior of said thin film, said second and third prisms suited for determining a propagation loss in said thin film as a result of passing light through said second and third prisms.