JPH04133456U - Infrared image sensor and infrared detector - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the sensitivity of infrared image sensors. [Structure] The refractive index of the surface layer 2 of the GdTe substrate forming the light receiving section 1 of the infrared image sensor 10 is larger than the refractive index of the deep layer 3. Infrared light 101 that enters the gap between the pixels of the light receiving section 1 from the direction A in the figure is largely bent by the surface layer 2 of the GdTe substrate and reaches the PN junction 5 . P.N.
The charges photoelectrically converted at the junction 5 are read out by the readout section 7 via the hybrid coupling section 6 .

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to infrared image sensors and infrared detectors, especially hybrid Related to type infrared image sensors, etc.

0002

[Conventional technology]

Infrared detectors are applied, for example, to hybrid infrared image sensors. ing. Conventional hybrid infrared image sensors prevent diffuse reflection of incident infrared light Therefore, the surface of the substrate of the light receiving section is mirror-finished. In addition, in conventional hybrid infrared image sensors, adjacent pixels In order to prevent crosstalk with the They are arranged two-dimensionally at pitch intervals equal to or larger than the pixel size.

0003

[Problem that the idea aims to solve]

However, in the conventional hybrid infrared image sensor mentioned above, the pixel Since a gap is formed between the pixels, infrared light that enters the gap between the pixels is The vehicle will pass through the route as it is. Therefore, the incident light enters the gap between these pixels. Infrared light is not photoelectrically converted and does not contribute to the image at all, so it may cause a decrease in sensitivity. There was a problem.

0004 This invention was devised in view of the above-mentioned problem. It is possible to use the infrared light that comes in for photoelectric conversion, thus improving sensitivity. The objective is to provide an infrared image sensor and an infrared detector that can

[0005]

[Means to solve the problem]

In order to achieve the above purpose, the infrared detector of the present invention detects the light received by the light receiving part. In an infrared detector that performs photoelectric conversion at the hybrid junction and reads out at the readout section, The refractive index of the surface layer of the substrate and the refractive index of the deep surface layer of the substrate in the light receiving section are different. In addition, the infrared image sensor of the present invention has the above-mentioned infrared detector. are arranged two-dimensionally so that images can be detected.

[0006]

【Example】

An embodiment of the present invention will be described below with reference to the drawings. Figure 1 shows a part of an infrared image sensor according to an application example of the infrared detector of the present invention. It is a partially cutaway perspective view, and FIG. 2 is a sectional view as well.

[0007] In these drawings, the infrared image sensor 10 includes a light receiving section 1, a hybrid It is composed of a code junction section 6, a readout section 7, and the like. The light receiving section 1 is formed of a GdTe (crystal) substrate. The GdTe substrate of the light receiving part 1 is , the refractive index of the substrate surface layer 2 is larger than the refractive index of the substrate deep layer 3. be. This change in refractive index occurs when it changes discontinuously and when it changes continuously. This includes both cases. The magnitude of the change in refractive index is determined by the received infrared light, which will be explained later. The light is appropriately selected so that the light is focused on the PN junction 6. Epitaxial Layer 4 is formed. Epitaxial layer 4 is made of HgGdTe on a GdTe substrate. It is grown and formed. A PN junction 5 is formed in the epitaxial layer 4. , this PN junction 5 performs photoelectric conversion. The hybrid coupling section 6 couples the PN junction section 5 and the reading section 7 together.

[0008] Next, the operation of the infrared image sensor 10 having the above configuration will be explained. The infrared light 100 incident on the light receiving section 1 from the direction A in the figure is transmitted to the surface layer 2 of the GdTe substrate. and penetrates the deep layer 3. At this time, the refractive index of the surface layer 2 of the GdTe substrate is different from that of the deep layer 3. Since the structure is configured so that the refractive index is larger than the refractive index, infrared light incident from direction A in the figure Among 100, infrared light 101 that tries to pass through the gap between pixels is transmitted through the GdTe substrate. The optical path is greatly bent at the surface layer 2 and reaches the PN junction 5. And this P The charge generated by photoelectric conversion at the N junction 5 is transferred via the hybrid junction 6. The data reaches the reading unit 7 and is read out by the reading unit 7.

[0009] Note that the present invention is not limited to the embodiment of the infrared image sensor described above. . For example, the present invention can be similarly applied to infrared detectors such as infrared sensors. .

0010

[Effect of the idea]

As explained above, the infrared image sensor and infrared detector of the present invention are capable of receiving Since the refractive index of the surface layer of the substrate in the optical part is changed relative to the refractive index of the deep layer of the substrate, Infrared light, which previously passed through the gaps between pixels and was not used for photoelectric conversion, can now be used for photoelectric conversion. available, thus increasing the sensitivity of infrared image sensors and infrared detectors can be done.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view showing an infrared image sensor according to an application example of the infrared detector of the present invention.

FIG. 2 is a cross-sectional view of FIG. 1;

[Explanation of symbols]

1... Light receiving section 2...Substrate surface layer 3...Deep part of the board 4...Epitaxial layer 5...PN junction 5...Hybrid joint part 7...Reading section 10...Infrared image sensor 100...Infrared rays

──────────────────────────────────────────────── ─── Continued from front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location G01J 5/48 D 8909-2G

Claims (2)

[Scope of utility model registration request] Claim 1: An infrared detector that photoelectrically converts light received by a light receiving part at a hybrid junction part and reading it out at a readout part, in which the refractive index of the surface layer of the substrate and the refractive index of the deep surface layer of the substrate in the light receiving part are different. An infrared detector characterized by the following. 2. An infrared image sensor characterized in that the infrared detectors according to claim 1 are arranged two-dimensionally to detect an image.