Spectroscopic sensor including interference filter unit having silicon oxide cavity

Patent metadata

Field	Value
Publication number	US-10168213-B2
Application number	US-201214349101-A
Country	US
Kind code	B2
Filing date	Sep 10, 2012
Priority date	Oct 4, 2011
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A spectroscopic sensor 1 comprises an interference filter unit 20, having a cavity layer 21 and first and second mirror layers 22, 23 opposing each other through the cavity layer 21, for selectively transmitting therethrough light in a predetermined wavelength range according to an incident position thereof; a light-transmitting substrate 3, arranged on the first mirror layer 22 side, for transmitting therethrough light incident on the interference filter unit 20, a light-detecting substrate 4, arranged on the second mirror layer 23 side, for detecting the light transmitted through the interference filter unit 20, and a first coupling layer 11 arranged between the interference filter unit 20 and the light-transmitting substrate 3. The cavity layer 21 and the first coupling layer 11 are silicon oxide films.

First claim

The invention claimed is:

1. A spectroscopic sensor comprising:
an interference filter unit, having a cavity layer and first and second mirror layers opposing each other through the cavity layer, for selectively transmitting therethrough light in a predetermined wavelength range according to an incident position thereof;
a light-transmitting substrate, arranged on the first mirror layer side, for transmitting therethrough light incident on the interference filter unit;
a light-detecting substrate, arranged on the second mirror layer side, for detecting the light transmitted through the interference filter unit; and
a first coupling layer arranged between the interference filter unit and the light-transmitting substrate;
wherein the cavity layer and the first coupling layer are silicon oxide films,
the thickness of the cavity layer varies between the first and second mirror layers,
the thickness of the first coupling layer varies such that the light-transmitting substrate and the light-detecting substrate are arranged parallel to each other,
the cavity layer has a filter region held between the first and second mirror layers, and a surrounding region continuously surrounding the whole perimeter of the filter region as seen in a direction in which the light-transmitting substrate and the light-detecting substrate oppose each other,
the cavity layer is formed continuously over the filter region and the surrounding region,
an entire face on the light-transmitting substrate side of the surrounding region has substantially the same height as a part of a face of the filter region on which the first mirror layer is formed located closest to the light-transmitting substrate or the entire face on the light-transmitting substrate side of the surrounding region is positioned nearer to the light-transmitting substrate than the part,
the filter region overlaps with a light-receiving unit of the light-detecting substrate and the surrounding region does not overlap with the light-receiving unit as seen in the direction in which the light-transmitting substrate and the light-detecting substrate oppose each other, and
the thickness of the filter region varies between the first and second mirror layers.

2. A spectroscopic sensor according to claim 1 , further comprising a second coupling layer arranged between the interference filter unit and the light-detecting substrate;
wherein the second coupling layer is a silicon oxide film.

3. A spectroscopic sensor according to claim 1 , further comprising an optical filter layer, formed on the light-transmitting substrate so as to oppose the first mirror layer, for transmitting therethrough light in the predetermined wavelength range.

4. A method for manufacturing a spectroscopic sensor according to claim 1 , the method comprising:
a step of forming the cavity layer made of a silicon oxide film;
a step of forming the first mirror layer on the cavity layer;
a step of joining the light-transmitting substrate on the first mirror layer via the first coupling layer made of a silicon oxide film
a step of forming the second mirror layer on the cavity layer; and
a step of joining the light-detecting substrate on the second mirror layer via a second coupling layer made of a silicon oxide film.

5. A method for manufacturing a spectroscopic sensor according to claim 4 , wherein, the step of forming the cavity layer forms the cavity layer made of the silicon oxide film by thermally oxidizing silicon.

6. A method for manufacturing a spectroscopic sensor according to claim 4 , wherein, the step of joining the light-transmitting substrate forms the first coupling layer made of the silicon oxide film by a film forming process using TEOS as a material gas.

7. A method for manufacturing a spectroscopic sensor according to claim 4 , wherein, the step of joining the light-detecting substrate forms the second coupling layer made of the silicon oxide film by a film forming process using TEOS as a material gas.

Assignees

• Shibayama Katsumi
• Kasahara Takashi
• Hamamatsu Photonics Kk

Inventors

• Shibayama Katsumi
• Kasahara Takashi

Classifications

• G01J3/45 Primary

  Interferometric spectrometry · CPC title

• G01J3/513

  having fixed filter-detector pairs · CPC title

• G01J3/2803

  using photoelectric array detector · CPC title

• G01J3/26 Primary

  using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters · CPC title

• G01J2003/2816

  Semiconductor laminate layer · CPC title