Process for Producing Solid-State Image Sensing Device, Solid-State Image Sensing Device and Camera
In the formation of a multilayer interference filter that is included in a solid-state imaging device, at the outset, a titanium dioxide layer ( 401 ), a silicon dioxide layer ( 402 ), a titanium dioxide layer ( 403 ), and a spacer layer are successively laminated on an interlayer insulation film ( 304 ) to form a lower films. Next, the reflectance characteristics of the lower films are measured to specify the thickness of the lower films. When the thickness is deviated from the design value, the thickness of the spacer layer ( 404 ), and the thickness of upper films that include titanium dioxide layers ( 407, 409 ) and silicon dioxide layers ( 408, 410 ) are changed. Then, according to the changes, the spacer layer ( 404 ) is etched to regulate the thickness, and the upper films are formed thereon.
1 . A manufacturing method of a solid-state imaging device that filters incident light with use of a multilayer interference filter, the multilayer interference filter including a spacer layer sandwiched between a first λ/4 multilayer and a second λ/4 multilayer, the manufacturing method comprising the steps of:
forming the first λ/4 multilayer;
forming the spacer layer on the first λ/4 multilayer;
specifying a film thickness by measuring a reflectance characteristic of a film that is composed of the first λ/4 multilayer and the spacer layer; and
forming the second λ/4 multilayer in a manner that, if the specified film thickness is smaller than a designed value of the film that is composed of the first λ/4 multilayer and the spacer layer, a film thickness of the second λ/4 multilayer is formed to be larger than a designed value of the second λ/4 multilayer, and, if the specified film thickness is larger than the designed value of the film that is composed of the first λ/4 multilayer and the spacer layer, the film thickness of the second λ/4 multilayer is formed to be smaller than the designed value of the second λ/4 multilayer.
2 . A manufacturing method of a color solid-state imaging device that filters incident light with use of a multilayer interference filter, the multilayer interference filter including a spacer layer sandwiched between a first λ/4 multilayer and a second λ/4 multilayer, the manufacturing method comprising:
a first step for, when forming the first λ/4 multilayer, forming a multilayer identical with the first λ/4 multilayer, in a reference area that is on a wafer excluding an area for forming the color solid-state imaging device;
a second step for, when forming the spacer layer on the first λ/4 multilayer, forming a layer in the reference area, the layer being identical with the spacer layer;
a third step for specifying a film thickness by measuring a reflectance characteristic of the reference area; and
a fourth step for forming the second λ/4 multilayer in a manner that, if the specified film thickness is smaller than a designed value of the reference area, a film thickness of the second λ/4 multilayer is formed to be larger than a designed value of the second λ/4 multilayer, and, if the specified film thickness is larger than the designed value of the reference area, the film thickness of the second λ/4 multilayer is formed to be smaller than the designed value of the second λ/4 multilayer.
3 . The manufacturing method of the solid-state imaging device of claim 2 further comprising:
a fifth step for etching parts of the spacer layer formed on the first λ/4 multilayer, each of the parts corresponding to respective transmitting light colors, and the layer identical with the spacer layer in the reference area, wherein
the third step is performed after the fifth step, and the reflectance characteristic of the reference area is measured for each film thickness of the parts of the spacer layer.
4 . The manufacturing method of the solid-state imaging device of claim 2 further comprising:
a sixth step for forming a multilayer identical with the second λ/4 multilayer in a reference area, wherein
the sixth step is performed in parallel with the third step.
5 . A solid-state imaging device that filters incident light with use of a multilayer interference filter, wherein
the multilayer interference filter includes a spacer layer sandwiched between a first λ/4 multilayer and a second λ/4 multilayer, and
a film thickness of the first λ/4 multilayer and a film thickness of the second λ/4 multilayer are different from each other.
6 . A solid-state imaging device including a multilayer interference filter, and monochromatic image sensors that detect lights of different wavelength bands, wherein
the monochromatic image sensors include (i) a first monochromatic image sensor for receiving outside light, and (ii) monochromatic image sensors except the first monochromatic image sensor, the monochromatic image sensors being for receiving light that is reflected by at least one other of the monochromatic image sensors.
7 . A camera including a solid-state imaging device that filters incident light with use of a multilayer interference filter, wherein
the multilayer interference filter includes a spacer layer sandwiched between a first λ/4 multilayer and a second λ/4 multilayer, and
a film thickness of the first λ/4 multilayer and a film thickness of the second λ/4 multilayer are different from each other.
8 . A camera including a solid-state imaging device that has a multilayer interference filter, and monochromatic image sensors that detect lights of different wavelength bands, wherein
the monochromatic image sensors include (i) a first monochromatic image sensor for receiving outside light, and (ii) monochromatic image sensors except the first monochromatic image sensor, the monochromatic image sensors being for receiving light that is reflected by at least one other of the monochromatic image sensors.