JPH0637291A - Infrared detector and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a method of manufacturing an infrared detecting device where an infrared image in focus can be obtained on an infrared detecting element even if it is located at the end of a large number of infrared detecting elements arranged in a line by a method wherein the photodetecting part of an infrared detecting element is located on the focal plane of an optical equipment. CONSTITUTION:Infrared detecting elements 4 formed on a compound semiconductor substrate 1 and semiconductor elements formed on another substrate or a wiring pattern are bonded together by pressure with metal bumps 5 and 8 for the formation of an infrared detecting device, where the compound semiconductor substrate 1 is cut into pieces of prescribed size, and each piece is provided with infrared detecting elements 4. The pieces of the divided substrate 1 are joined together making cut surfaces butt against each other so as to arrange the detecting elements 4 on the focal plane 13 of an optical equipment of an infrared detecting device composed of the elements 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared detecting device and a method for manufacturing the same. Mercury with a narrow energy gap
An infrared detecting element is formed on a compound semiconductor substrate such as cadmium tellurium (HgCdTe), and a signal processing element for processing a detection signal of the detecting element is formed on a semiconductor substrate such as a silicon (Si) substrate.

In addition, indium (In)
The hybrid type infrared detection device is formed by pressure bonding using the metal bumps.

[0003]

2. Description of the Related Art A conventional method of manufacturing such an infrared detecting device will be described. As shown in FIG. 4 (a), a p-type HgCdTe crystal 2 is formed on a cadmium tellurium (CdTe) substrate 1 by a liquid phase epitaxial growth method or the like, and boron (B) ions are formed in a predetermined region of the HgCdTe crystal 2. Are ion-implanted to form an n-type layer 3 to provide a pn junction, and an infrared detection element 4 formed of a photodiode and arranged in an array is formed.

Then, as shown in FIG. 4B, a metal bump 5 made of In is deposited on the infrared detecting element 4 by a method such as vapor deposition. On the other hand, a signal processing element 6 such as a charge transfer element for processing the detection signal obtained by the infrared detection element 4 is formed on the Si substrate 7, and an In metal bump 8 is also vapor-deposited on the signal processing element 6. And the like.

Both boards 1, 7 are set on the pressing jigs 9, 11 of the flip chip bonder device, and both boards 1, 7 are placed.
The In metal bumps 5 and 8 provided on the elements 4 and 6 are pressed and pressure-bonded to form an infrared detection device.

[0006]

By the way, it is desired that such an infrared detecting device has a performance with a higher spatial resolution, and accordingly, an array-like infrared detecting device having an increasing number of elements is required. Required.

However, the wavelength of infrared rays is from several μm to several tens of μm.
It is impossible to form an element size smaller than this wavelength region because the element loses sensitivity and loses its sensitivity. Therefore, since there are restrictions on the size of the element, if a large number of infrared detecting elements are provided in a row, the dimension from one end to the other end of the infrared detecting elements arranged in a row may be several cm long. .

When light is incident on such an infrared detecting element, as shown in FIG. 4 (c), the infrared ray indicated by the arrow A is condensed by using the condenser lens 12 of the optical instrument to collect the infrared detecting element 4 Is incident on one end of the infrared detector
If the dimension from 4A to the other end 4B is long, the focal plane 13 of the condenser lens 12 may not match the light receiving surface of the infrared detection element 4, and there is a problem that a clear infrared image cannot be obtained.

The present invention solves the above-mentioned problems. Even when the infrared detection elements are arranged in a long array, the focal plane of the condenser lens of the optical instrument of the detection device receives light from the detection elements. It is an object of the present invention to provide an infrared detection device that solves the inconvenience of not matching parts and a manufacturing method thereof.

[0010]

In an infrared detecting device of the present invention, an infrared detecting element formed on a compound semiconductor substrate and a semiconductor element formed on another substrate or a wiring pattern are pressure-bonded to each other by using metal bumps. In the infrared detecting device, the cut surfaces of the compound semiconductor substrate cut into a predetermined size so as to include a plurality of infrared detecting elements are butted against each other, and the plurality of infrared detecting elements are It is characterized in that it is arranged on the focal plane of the lens of the optical instrument of the infrared detector to be formed.

Further, in the method for manufacturing an infrared detecting device of the present invention, the infrared detecting element formed on the compound semiconductor substrate and the semiconductor element or wiring pattern formed on another substrate are pressure-bonded to each other by using metal bumps. In manufacturing an infrared detecting device, the compound semiconductor substrate having the infrared detecting element formed thereon is cut into a predetermined size so as to include a plurality of infrared detecting elements, and the cut surfaces of the cut compound semiconductor substrate are butted against each other. , The infrared detecting element arranged on the pressing jig having a curved surface that matches the focal plane of the lens of the optical instrument of the infrared detecting device to be formed, and the infrared detecting element and the other pressing jig. It is characterized in that it is pressure-bonded to a semiconductor element installed on another substrate or a wiring pattern.

[0012]

According to the infrared detecting device of the present invention, a compound semiconductor substrate having a large number of infrared detecting elements arranged in an array is cut into a predetermined size so as to include a plurality of the infrared detecting elements, and the cut compound semiconductor substrate. The cut surfaces of the above are abutted to each other so that the plurality of infrared detecting elements are aligned with the focal plane of the lens of the optical machine.

In the method of the present invention, the compound semiconductor substrate on which the array-shaped infrared detecting elements are formed is divided into a plurality of blocks including a predetermined number of the detecting elements. Then, the divided compound semiconductor substrates are placed on a pressing jig having a curved surface that matches the focal plane of the condensing lens of the optical instrument of the infrared detection device to be formed, with the cut surfaces abutting each other.

On the other hand, the Si substrate on which the signal processing element is formed is set on a flat pressing jig, and the metal bump of In is kept high so as to reach the end of the element where both elements are arranged. Form bumps.

By doing so, the vicinity of the light receiving portion of the detecting element at the end of the infrared detecting element array is less likely to be displaced from the focal plane of the condenser lens of the optical instrument, and a clear infrared image can be obtained. become.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a sectional view of an infrared detection device of the present invention. As shown in the figure, a p-type HgCdTe crystal 2 is provided on a cadmium tellurium (CdTe) substrate 1, an n-type layer 3 is provided in a predetermined region of the HgCdTe crystal 2 to form a pn junction, and an infrared detection element composed of a photodiode is provided. 4 are provided in an array.

The CdTe substrate 1 is divided into a plurality of predetermined blocks so as to include a predetermined number of infrared detecting elements 4 in the infrared detecting element array, and the infrared detecting elements 4 are arranged on the infrared detecting elements 4.
The metal bump 5 made of In is provided by a method such as vapor deposition.

Further, metal bumps 8 of In are also formed on the signal processing element 6 formed on the Si substrate 7 by a vapor deposition method or the like. Then, the cut CdTe substrate 1 is vacuum-adsorbed on a crimping jig having a curved surface matching the focal plane 13 of the lens described later by abutting the cut surfaces thereof, to form the metal bumps 5 formed on the CdTe substrate 1. The metal bumps 8 are pressure-bonded to each other.

With this arrangement, the light receiving portions of the infrared detecting elements 4 arranged in an array match the focal plane 13 of the condenser lens described above, and the infrared detecting elements arranged in a row of long dimensions. Since the vicinity of the light receiving portion is also aligned with the focal plane 13 of the condenser lens at both ends of 4, the infrared detector capable of forming a clear infrared image without defocusing can be obtained.

A method of manufacturing such an infrared detecting device of the present invention will be described. As shown in FIG. 2 (a), a p-type HgCdTe crystal 2 is formed on a cadmium tellurium (CdTe) substrate 1 by a liquid phase epitaxial growth method or the like, and boron (B) ions are formed in a predetermined region of the HgCdTe crystal 2. Are ion-implanted to form an n-type layer 3 to provide a pn junction, and the infrared detection elements 4 formed of photodiodes are formed in an array.

Next, as shown in FIG. 2B, the CdTe substrate 1 is divided into a plurality of predetermined blocks so that a predetermined number of infrared detecting elements 4 in the infrared detecting element array are included. Then, as shown in FIG. 2 (c), this infrared detecting element 4
A metal bump 5 made of In is formed on the above by a method such as vapor deposition.

The height of the metal bumps 5 is the same as the height of the metal bumps 5A, 5B formed on the infrared detecting elements 4A, 4B at both ends of the row, and the height of the metal bumps 5A, 5B formed on the infrared detecting elements 4C at the center of the row. Try to keep it higher than 5C height.

Further, metal bumps 8 of In are also formed on the signal processing element 6 formed on the Si substrate 7 by the vapor deposition method or the like. The height of this metal bump 8 is equal to the signal processing elements 6A, 6 at both ends of the row.
The height of the metal bumps 8A, 8B formed on B is kept higher than the height of the metal bumps 8C formed on the signal processing element 6C at the center of the column.

Next, as shown in FIG. 3 (a), the CdTe substrate 1 cut into the blocks is set on the pressing jig 9 by using a vacuum suction method or the like. The curved surface 21 of this pressing jig 9 is
As shown in 4 (c), it is aligned with the focal plane 13 of the condenser lens of the optical instrument used in the infrared detector to be formed.

Further, the signal processing element 6 and the Si substrate 7 on which the metal bumps 8 are formed are placed on a flat pressing jig 11, and the metal bumps 5 formed on the CdTe substrate 1 and the metal bumps 8 are pressure-bonded to each other. .

FIG. 3 (b) shows a state in which this pressure bonding is performed. In the case of this pressure bonding, the flat pressing jig 11 described above,
It is formed using a transparent plastic plate or the like that can transmit infrared rays from the back side.

Then, infrared rays are made incident from the rear surface side of the Si substrate 7 using an alignment device, and the signal processing element and the infrared ray detecting element are aligned using the incident infrared image, and then the metal bumps 5, 8 are formed. Crimping and joining each other.

By doing so, the light receiving portions of the infrared detecting elements 4 arranged in an array come to coincide with the focal plane 13 of the condenser lens described above, and the infrared detecting elements arranged in a row of long dimensions. Since the vicinity of the light receiving portion is also aligned with the focal plane 13 of the condenser lens at both ends of 4, the infrared detector capable of forming a clear infrared image without defocusing can be obtained.

In the present embodiment, the signal processing element 6 formed on the Si substrate 7 is used as the element for bonding the infrared detecting element 4 to the metal bump, but as another embodiment, the wiring pattern connected to the signal processing element 6 is used. Formed on another insulating substrate,
The wiring pattern formed on this insulating substrate and the infrared detection element 4 may be connected by a metal bump.

[0030]

As described above, according to the manufacturing method of the infrared detecting device of the present invention, the vicinity of the light receiving portion of the infrared detecting element constituting the detecting device comes to coincide with the focal plane of the optical instrument, There is an effect that an infrared detection device for a clear infrared image without defocusing can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of an infrared detection device of the present invention.

FIG. 2 is an explanatory diagram of a method for manufacturing an infrared detection device of the present invention.

FIG. 3 is an explanatory diagram of a method for manufacturing an infrared detection device of the present invention.

FIG. 4 is an explanatory diagram of a conventional method for manufacturing an infrared detection device and an explanatory diagram of its inconvenient state.

[Explanation of symbols]

 1 CdTe substrate 2 HgCdTe crystal 3 n-type layer 4 infrared detector 5,8 metal bump 9,11 pressing jig 13 focal plane 21 curved surface

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location G01J 5/30 8909-2G G02B 3/00 A 8106-2K 7/04 H01L 31/0264 7210-4M H01L 31/08 N (72) Inventor Ho Yamamoto 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited

Claims (2)

[Claims] 1. An infrared detection element (4) formed on a compound semiconductor substrate (1) and a semiconductor element or wiring pattern formed on another substrate are pressure-bonded to each other using metal bumps (5, 8). In the infrared detecting device, the plurality of infrared detecting elements (4) are formed by abutting the cut surfaces of the compound semiconductor substrate (1) cut into a predetermined size so as to include the plurality of infrared detecting elements (4). Is arranged on the focal plane (13) of the lens of the optical instrument of the infrared detection device formed by using the detection element (4). 2. An infrared sensing element (4) formed on a compound semiconductor substrate (1) and a semiconductor element or wiring pattern formed on another substrate are pressure-bonded to each other by using metal bumps (5, 8). In manufacturing an infrared detecting device to be formed, a compound semiconductor substrate on which the infrared detecting element (4) is formed
(1) is cut into a predetermined size so as to include a plurality of infrared detecting elements (4), and the cut surfaces of the cut compound semiconductor substrate (1) are abutted against each other, and the infrared detecting device is provided with an optical instrument. It is arranged on a pressing jig (9) having a curved surface (21) that matches the focal plane of the lens, the infrared detecting element (4) arranged on the pressing jig (9), and another pressing jig ( 11) A method for manufacturing an infrared detecting device, which comprises pressure-bonding a semiconductor element (6) formed on another substrate (7) or a wiring pattern on the substrate (7).