JPH04152225A - Manufacture of infrared ray sensor - Google Patents

Abstract

PURPOSE:To align chips of infrared ray sensing element having different characteristics precisely and place on a cooling stage by forming a plurality of infrared ray receiving parts on the chip surface in mating with a V-groove provided at the rear of the chip. CONSTITUTION:A V-groove 24 is formed in a sapphire base board 22 using a diamond tool or cutter, and HgCdTe crystals 26 are adhered to the opposite side of this sapphire base board 22. A comb-teeth form element part 28 is formed on these HgCdTe crystals 26 by mean of etching. An infrared ray receiving part 30 is formed in each element part 28 by photo-lithographic method by reference to the V-groove 24 in the base board 22. Because the base board 22 and HgCdTe crystals 26 are transparent, it is practicable to observe the V-groove 24 from above easily and the infrared ray receiving part 30 can be formed in alignment with the V-groove 24. The V-grooves 24 are aligned with each other from the same side with a projection 20 formed on a cooling stage 12 the infrared ray sensing element, and each base board 22 is adhered onto this stage 12.

Description

[Detailed Description of the Invention] Summary: An object of the present invention is to provide an infrared detector manufacturing method in which a plurality of infrared sensing element chips with different characteristics can be accurately aligned and mounted on a cooling stage. In a method for manufacturing an infrared detector configured by mounting a plurality of infrared sensing element chips on a cooling stage, a V-groove is provided on the back side of the infrared sensing element chip, and the chip surface is aligned with the V-groove. A plurality of infrared receiving portions are formed in the cooling stage, and the V grooves of the plurality of chips are brought into contact from the same direction with an elongated protrusion provided on the cooling stage to align the plurality of chips in a line. It is configured by gluing it to the cooling stage.

Industrial applications The present invention relates to a method of manufacturing an infrared detector.

Infrared sensors (detectors) can detect the presence, shape, temperature, composition, etc. of a target object without coming into contact with it, so it can be used for weather observation using artificial satellites, crime prevention, disaster prevention, geological and resource surveys, and medical treatment using infrared thermography. It is used in many fields such as business.

Such infrared sensors include front type sensors using pyroelectric elements, thermopiles, etc., and photoelectric effect type (quantum type) sensors using semiconductors.

In general, previous-type sensors have no wavelength dependence in sensitivity, but they have low sensitivity and slow response speed, making them unsuitable as real-time infrared sensors. On the other hand, photoelectric effect sensors have high sensitivity and fast response speed, but require cooling of the element to approximately liquid nitrogen temperature in order to obtain sensitivity. Photoelectric effect type infrared sensors are classified into photoconductive type, photovoltaic type, and MIS type.

Among these, the photoconductive type sensor utilizes a change in resistance upon irradiation with light, and for example, one using an infrared sensing element chip made of a compound semiconductor crystal such as HgCdTe is known.

Such a photoconductive type infrared sensing element is used after being cooled to approximately the temperature of liquid nitrogen, as described above, in order to obtain sensitivity. Therefore, the infrared sensing element is usually glued onto a cooling stage of an insulated container.

By the way, in remote sensing from an artificial satellite, if you want to use various wavelength bands, you need to fabricate the sensing element by dividing it into two parts or into multiple pieces, align the light-receiving part of each element chip accurately, and then cool it. Must be mounted on stage.

BACKGROUND OF THE INVENTION A manufacturing method and structure of a conventional infrared detector will be described with reference to FIGS. 4 and 5. Two chips 4a and 4b are aligned on the cooling stage 2 using an optical microscope, and then mounted and fixed with adhesive. 4 chips each
A, 4b are etched to form a plurality of horizontal tooth-shaped sensing element portions 6, and each sensing element portion 6 is provided with a light receiving portion 8. Alignment using an optical microscope is performed using center lines 10a and l of the light receiving portions 8 of each chip 4a and 4b.
Qb is aligned in a straight line, and after alignment, each chip 4a, 4b is attached to the cooling stage 2 with adhesive.
It is fixed at Chip 4a.

4b is made of, for example, HgCdTe, and is configured to have sensitivity in different wavelength bands by changing its composition.

Problems to be Solved by the Invention Conventionally, the positioning of the light-receiving parts of each chip 4a and 4b was performed visually using an optical microscope, resulting in a positional deviation of about 10 μm, which caused distortion in the image. There was a problem that this occurred.

The present invention has been made in view of these points, and its purpose is to manufacture an infrared detector in which infrared detecting element chips with different characteristics can be accurately aligned and mounted on a cooling stage. The purpose is to provide a method.

Means for Solving the Problem In a method for manufacturing an infrared detector consisting of a plurality of infrared detecting element chips mounted on a cooling stage, a V-groove is provided on the back side of the infrared detecting element chip, and a V-groove is aligned with the V-groove. A plurality of infrared light receiving sections are formed on the chip surface. Then, the V-grooves of the plurality of chips are brought into contact with the elongated projections provided on the cooling stage from the same direction to align the plurality of chips in a line, and the plurality of chips are bonded onto the cooling stage.

Function: Since a plurality of infrared light receiving sections are formed on each chip in accordance with the V groove provided on the back side of the chip, these infrared light receiving sections can be formed accurately in accordance with the V groove for all chips. In addition, by bringing the V grooves of each chip t1 into contact with the protrusions on the cooling stage from the same direction, the light receiving portions of each chip can be accurately aligned.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view of an embodiment of the present invention, and FIG. 2 is an enlarged view of the main parts thereof. A V-groove 16 is formed on the back surface of the infrared sensing element chips 14a and 14b formed from HgCdTe, and each chip 14a,
A plurality of infrared light receiving sections 18 are formed in 14b. An elongated protrusion 20 whose height is lower than the depth of the V-groove 16 is fixed on the cooling stage 12, and the chip 14 is attached to this protrusion 20.
By bringing the V grooves 16 of the chips 14a and 14b into contact with each other from the same direction as shown in FIG. 2, the infrared receiving portions 18 of the chips 14a and 14b are accurately aligned in a straight line. In this aligned state, each chip 14a, 14b is bonded to the cooling stage 12 with an adhesive.

Each chip 14a, 14b is formed with a different composition and is sensitive to different wavelength bands, and an infrared detector manufactured by the method of the present invention is mounted on an artificial satellite to perform remote sensing in different wavelength bands. It can be carried out.

Next, with reference to FIG. 3, an example of a method for manufacturing an infrared sensing element will be described. In FIG. 3, (al) to (a
4 is a plan view, and (bl) to (b4) are right side views corresponding to each plan view.

First, as shown in FIGS. 3(al) and (bl), a V-groove 24 is formed in the sapphire substrate 22 using a diamond tool, cutter, or the like. (2) As shown in (a2) and (b2), an HgCdTe crystal 26 is adhered to the opposite side of the sapphire substrate 22 in which the groove 24 has been formed. Then, (a3
) and (b3), HgC is removed by etching.
A plurality of comb-shaped element portions 28 are formed on the dTe crystal 26 . Then, as shown in (a4) and (b4), infrared light receiving portions 30 are formed in each element portion 28 by photolithography using the V-groove 24 of the sapphire substrate 22 as a reference.

In this case, the sapphire substrate 22 and the HgCd7e crystal 26
Since the V-groove 24 is transparent, the V-groove 24 can be easily observed from above, and the infrared light receiving section 30 can be formed in alignment with the V-groove 24.

As an alternative, a double-sided aligner may be used, and while checking the V-groove 24 formed on the back surface of the sapphire substrate 22 by the double-sided aligner, the infrared receiving portion 30 may be formed using this V-groove 24 as a reference. You may also do so.

The thus manufactured infrared sensing elements are aligned by bringing their respective V grooves 24 into contact with the protrusions 20 formed on the cooling stage 12 from the same direction, as shown in FIGS. 1 and 2. , each sapphire substrate is bonded onto the cooling stage 12.

Instead of forming a V-groove on the sapphire substrate, a V-groove is formed on the 31 substrate using anisotropic etching, and this 81 substrate is adhered to the back surface of the sapphire substrate, and then FIG. 3 (a2),
(b2) The following steps may be executed. This method uses anisotropic etching, so ■
The grooves are formed accurately, and the infrared light receiving portions of each chip can be aligned with higher precision.

In each of the embodiments described above, a V-groove is formed, but the groove is not limited to a V-groove, and for example, a U-groove may be formed.

Effects of the Invention Since the present invention is configured as described in detail above, it has the effect that infrared sensing element chips having different characteristics can be mounted on a cooling stage with their light receiving parts aligned accurately.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an embodiment of the present invention, Fig. 2 is an enlarged view of main parts of the embodiment, Fig. 3 is a diagram showing the manufacturing process of an infrared sensing element chip, Fig. 4 is a plan view of a conventional example, and Fig. 5 The figure is a front view of a conventional example. 2...Cooling stage, 4a, 14b...Detecting element chip, 6.24...V groove, 8.30...Infrared receiving section, 0...Protrusion, 2...Sapphire substrate, 6 -Hg Cd Te crystal.

Claims (1)

[Claims] 1. A method for manufacturing an infrared detector configured by mounting a plurality of infrared sensing element chips (14a, 14b) on a cooling stage (12), comprising: A V groove (16) is provided on the back side, and the chips (14a, 14b) are aligned with the V groove (16).
A long slender projection (20) formed on the surface of which a plurality of infrared receiving portions (18) are formed and provided on the cooling stage (12).
V grooves (16) of the plurality of chips (14a, 14b)
A method for manufacturing an infrared detector, characterized in that the plurality of chips (14a, 14b) are bonded to the cooling stage (12) by aligning the plurality of chips in a line by bringing them into contact with each other from the same direction. 2. The infrared detector according to claim 1, characterized in that a V-groove (24) is formed on the back surface of the sapphire substrate (22), and an infrared sensing element chip (26) is bonded to the surface of the sapphire substrate (22). Production method. 3. A V-groove is formed on the back surface of the Si substrate by anisotropic etching, a sapphire substrate is bonded to the surface of the Si substrate, and an infrared sensing element chip is bonded onto the sapphire substrate. A method for manufacturing an infrared detector. 4. The method for manufacturing an infrared detector according to any one of claims 1 to 3, characterized in that a U-groove is formed in place of the V-groove (16, 24).