Film formation control device, film formation device and film formation method

1 . A film formation control device comprising:

a light source that irradiates a substrate with light, the substrate being disposed on a rotating body;

a light receiving unit that receives transmitted light or reflected light, the transmitted light being a light emitted from the light source and transmitted through a layer of a thin film formed on the substrate, the reflected light being a light emitted from the light source and reflected by the layer;

a positional information acquisition unit that acquires positional information corresponding to a position in a circumferential direction of the rotating body; and

a control unit that controls a film formation condition,

the control unit comprising:

a timing control unit that determines a targeted position of the substrate based on the positional information in the circumferential direction of the rotating body acquired by the positional information acquisition unit and controls timing of receiving the transmitted light or reflected light of the light emitted from the light source to the substrate at the targeted position;

a film thickness determination unit that calculates a film thickness of each layer of the thin film composed of multiple layers based on the transmitted light or reflected light received by the light receiving unit and determines a film thickness difference between the calculated film thickness of each layer and a target film thickness of each layer constituting the thin film having a desired spectral characteristic;

a spectral characteristic determination unit that determines whether a spectral characteristic of the thin film obtained by a film formation process falls within an allowable range of the desired spectral characteristic; and

a film formation condition setting unit that,

wherein:

i) when the spectral characteristic of the thin film obtained by the film formation process falls within the allowable range of the desired spectral characteristic, the film formation condition setting unit does not adjust the film formation condition for each layer;

ii) when the spectral characteristic of the thin film obtained by the film formation process falls outside the allowable range of the desired spectral characteristic, determine whether the film thickness difference exceeds a predetermined value,

ii)-1: when the film thickness difference of at least one layer is more than the predetermined value, adjusts the film formation condition for the at least one layer to be formed on a subsequent substrate so that the film thickness of each layer to be formed on the subsequent substrate becomes the target film thickness; and

ii)-2: when the film thickness difference of the at least one layer is equal to or less than the predetermined value, the film formation condition setting unit does not adjust the film formation condition for each layer.

2 . The film formation control device according to claim 1 , wherein the film thickness determination unit calculates a transmittance from an intensity of the transmitted light received by the light receiving unit or calculates a reflectance from an intensity of the reflected light and calculates the film thickness of each layer from the calculated transmittance or reflectance.

3 . The film formation control device according to claim 2 , wherein the film thickness determination unit compares the intensity of the transmitted light or reflected light transmitted through or reflected from each layer constituting the thin film with a reference intensity to calculate the thickness of each layer,

wherein the reference intensity is an intensity when the light emitted from the light source is received by the light receiving unit only through a film formation space without passing through the substrate and each layer constituting the thin film or an intensity when the light emitted from the light source is reflected only by the substrate before the film formation process and received by the light receiving unit.

4 . The film formation control device according to claim 3 , wherein a through-hole is formed at a concyclic position on the substrate disposed on the rotating body, and

the intensity when the light emitted from the light source is transmitted through the through-hole and received by the light receiving unit is set as the reference intensity.

5 . The film formation control device according to claim 1 , wherein

the positional information acquisition unit comprises:

a reflective plate disposed on the rotating body; and

a laser device that irradiates the reflective plate with laser light and receives reflected laser light reflected from the reflective plate, and

the timing control unit acquires the positional information of the rotating body from an intensity distribution of the reflected laser light received by the laser device and controls, based on the acquired positional information, a first timing at which the light source emits pulsed light and a second timing at which the light receiving unit receives the pulsed light.

6 . The film formation control device according to claim 1 , wherein

the positional information acquisition unit comprises:

a rotating shaft that rotates together with the rotating body;

a reflective plate that is disposed on the rotating shaft and includes two notch portions;

a light projecting unit that projects light toward the reflective plate; and

a projected light receiving unit that receives light from the light projecting unit, and

the timing control unit acquires the positional information of the rotating body from an intensity distribution of the light received by the projected light receiving unit and controls, based on the acquired positional information, a first timing at which the light source emits pulsed light and a second timing at which the light receiving unit receives the pulsed light.

7 . A film formation device comprising:

a film formation chamber that is set to a predetermined pressure and includes a rotating body on which a substrate is disposed;

a film formation processing unit that executes a film formation process for a thin film composed of multiple layers in accordance with a predetermined film formation condition; and

a film formation control device according to claim 1 ,

wherein the film formation control device sets the predetermined film formation condition for the film formation processing unit.