JPH09298285A - Integrated circuit device incorporating light receiving elements and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an integrated circuit device incorporating a plurality of light receiving elements wherein an integrated circuit and the plurality of light receiving elements are formed adjacent to each other on a semiconductor substrate, which can be made small in size and low in power consumption, can improve its productivity and be made low in its manufacturing cost; and also to provide a method for manufacturing the integrated device. SOLUTION: Three light receiving parts (N<-> epitaxial layer 3) are divided on a semiconductor substrate 1 as surrounded by a P<+> type element isolation diffusion region 2b and a P<+> type buried region 2a. In this way, the high-concentration region having the same conduction type as the semiconductor substrate 1 is subjected to an element isolation of the light receiving region by means of burying and diffusing processes used at the time of forming a transistor to thereby form a light receiving part. As a result, since minor carriers generated by light illuminated on an area other than the light receiving part can be captured, cross-talk can be prevented. Since an additional formation step in the same process as an integrated circuit is eliminated, its productivity can be improved. Further, since fine processing is possible, its miniaturization can be realized. Since it can be made in the form of an integrated circuit, a low power consumption can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated circuit device with a built-in light receiving element in which a plurality of light receiving elements are formed on the same substrate as an integrated circuit and a method for manufacturing the same, and more particularly to a compact disc (hereinafter abbreviated as "CD"). ) And the like, the present invention relates to a device-integrated integrated circuit device for an optical disk pickup device and a method for manufacturing the same.

[0002]

2. Description of the Related Art Along with the progress of multimedia, a technique of integrating an optical semiconductor element and an integrated circuit is becoming popular. In particular, it has been put to practical use in various fields such as an integrated circuit device with a built-in light receiving element in which a plurality of semiconductor light receiving elements are arranged in a light receiving portion, and a pickup signal reading used in a CD or the like.

As such a semiconductor light receiving element, for example, a light receiving element as described in Japanese Patent Application Laid-Open No. 3-156980, that is, "in a light receiving element in which a plurality of light receiving regions are formed in a light absorbing region of a semiconductor crystal, , A light receiving element in which a part of the light absorption region between the adjacent light receiving regions is depleted. ”
It has been known.

FIG. 5 shows the conventional semiconductor light receiving element described above.
This will be specifically described with reference to FIG. 5A and 5B are views for explaining a conventional semiconductor light receiving element, FIG. 5A is a plan view thereof, and FIG. 5B is a sectional view taken along line XX of FIG.

As shown in FIG. 5A, a conventional semiconductor light receiving element includes a light receiving element portion 12, a p-side electrode 13 of the light receiving element, a non-doped InGaAs light receiving layer (light absorbing region) 18, and a peripheral portion thereof. It is composed of a diffusion region 15 that forms a depleted portion including the electrode 13a for taking out electric charges to the outside. Then, as shown in FIG. 5B, after a non-doped InGaAs absorption layer (light absorption region) 18 is grown on the n ⁺ type InP substrate 19 by 5 μm, Zn is selectively diffused to form a light receiving portion. And a diffusion region (light receiving region) 14 and a diffusion region (P ⁺ region) 15 that forms a depleted portion including its peripheral portion. Further, the respective light receiving regions 14 are formed at a distance of 150 μm from the boundary. In FIG. 5B, 16 is an antireflection film and 17 is an n-side electrode.

[0006]

By the way, the above-mentioned conventional semiconductor light receiving element has the following first to third problems.

(First Problem) In the conventional semiconductor light receiving element, it is necessary to increase the element size in order to prevent crosstalk, which makes it difficult to miniaturize the element. That is, the first problem is that in the conventional technique, it is necessary to separate them by several hundreds of μm in order to prevent crosstalk between the light receiving portions, and therefore, the element cannot be downsized. The reason is that the minority carriers generated between the light receiving portions need to be captured in the depletion layer region below the P ⁺ region.

(Second problem) Further, since the semiconductor light receiving element cannot be formed by using the manufacturing process of the integrated circuit, the number of manufacturing steps is increased, and it is difficult to reduce the productivity and the cost. Was becoming. That is, the second problem is that the conventional technique cannot be manufactured by the standard manufacturing process of the integrated circuit in order to form the PIN-PD structure, the P ⁺ region and the like. The reason is that there is no "transistor, resistance, etc. considering the light receiving element" in the process of pursuing the characteristics of the integrated circuit.

(Third Problem) Further, in order to enhance the crosstalk effect, it is generally necessary to widen the depletion layer in the P ⁺ region, but for this purpose, high reverse bias application is required. As a result, it has been difficult to reduce power consumption. That is, the third problem is that in the conventional technique, in order to improve the crosstalk effect, the depletion layer in the P ⁺ region must be widened. Therefore, it is necessary to apply a reverse bias of several tens of volts, and it is impossible to reduce the power consumption. The reason is that the depletion layer spreads little at a reference voltage of about 5 V of the integrated circuit, and minority carriers generated from deeply incident light cannot be captured.

(Object of the Invention) The present invention has been made in view of the above-mentioned first to third problems in the prior art, and the object (technical problem) is to provide a semiconductor substrate on the semiconductor substrate. In a light receiving element built-in integrated circuit device and a manufacturing method thereof, in which an integrated circuit and a plurality of light receiving elements are formed adjacently,
An object of the present invention is to provide an integrated circuit device with a built-in light receiving element that prevents crosstalk between a plurality of light receiving elements, realizes miniaturization, improvement in productivity, cost reduction, and low power consumption, and a manufacturing method thereof.

[0011]

The present invention provides a means for achieving the above-mentioned object, in particular, when forming an integrated circuit and a plurality of light receiving elements adjacent to each other on a semiconductor substrate, each light receiving portion is formed. The feature is that minority carriers diffused in all directions between the adjacent and adjacent integrated circuits and the light receiving section can be suppressed by using a standard manufacturing process of the integrated circuit.

That is, the integrated circuit device with a built-in light-receiving element according to the present invention has the following features: "A second conductive type high concentration region formed on a first conductive type semiconductor substrate forming an integrated circuit; A conductive type region is formed, and the second conductive type region is divided into a plurality of regions by the first conductive type high-concentration region.
An integrated circuit device with a built-in light receiving element, wherein the second conductivity type region is formed so as to be surrounded by the first conductivity type high concentration region. (Claim 1).

Further, the integrated circuit device with a built-in light receiving element according to the present invention has a feature that "the second conductivity type is formed on the high-concentration region of the first conductivity type formed on the semiconductor substrate of the first conductivity type forming the integrated circuit. A light receiving region characterized by forming a conductive type region, dividing the light receiving region by the second conductivity type high concentration region, and forming the light receiving region by the first conductivity type high concentration region. An integrated circuit device with a built-in element. "(Claim 2).

Further, the method for manufacturing an integrated circuit device with a built-in light receiving element according to the present invention is "a method for manufacturing an integrated circuit device with a built-in light receiving element in which an integrated circuit and a plurality of light receiving elements are formed adjacently on a semiconductor substrate. Manufacturing of an integrated circuit device with a built-in light receiving element, characterized in that minority carriers that diffuse in all directions are suppressed between each light receiving part and between an adjacent integrated circuit and a light receiving part using a standard manufacturing process of an integrated circuit. Method."
(Claim 3) is the gist.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. As described above, the present invention facilitates a conventional crosstalk having a plurality of light receiving regions by using a standard manufacturing process of an integrated circuit. It was made in order to solve the above problems and to achieve miniaturization, low power consumption, improved productivity, and low price.

[0016] Then, the light-receiving element built integrated circuit device according to the present invention, specifically, will be detailed in later, as shown in FIG. 1, on a semiconductor substrate 1, P ⁺ -type buried region 2a and N ^{It has a −} type epitaxial layer 3 and a P ⁺ type element isolation diffusion region 2b. Similarly, as shown in FIG. 2, N ⁻
It has an N ⁺ type element isolation diffusion region 7 for element isolation of the type epitaxial layer 3 and a P ⁺ type light absorption diffusion region 8 for forming a light receiving portion.

[0017]

The operation of the present invention will be described with reference to the specific example shown in FIG. 1, which will be described in detail later,
FIG. 2 is a diagram showing a cross-sectional structure of a “plurality of light receiving portions” according to the present invention, in which an N ⁻ type epitaxial layer 3 is formed on a semiconductor substrate 1, and a P ⁺ type buried region 2a and a P ⁺ type element are formed. It is formed so as to be divided so as to be surrounded by the separation region 2b.

The N ⁻ type epitaxial layer 3 is used as a cathode region, while the P ⁺ buried region 2a and the grounded P ⁺ type element isolation diffusion region 2b are used as an anode region.
In addition, by forming the light receiving region so that each width of the P ⁺ type element isolation diffusion region 2b is adjacent to several μm, most of the minority carriers generated in the regions other than the light receiving region are stored in the P ⁺ type element isolation diffusion region 2b. And the crosstalk between the light receiving portions can be greatly reduced, and the light receiving region is formed by using the standard process of the integrated circuit. Therefore, there is an effect that the power consumption can be reduced without additional steps.

[0019]

EXAMPLES Examples of the present invention will now be described with reference to the drawings, but the present invention is not limited to the following examples and is modified within a range not departing from the gist of the present invention. ， It is possible to make changes.

(Embodiment 1) FIG. 1 is a sectional view of a semiconductor light receiving element showing an embodiment (Embodiment 1) of an integrated circuit device with a light receiving element according to the present invention.

In the semiconductor light receiving element of the integrated circuit device with a built-in light receiving element according to the first embodiment, three light receiving portions (N ⁻ type epitaxial layer 3) are formed on the semiconductor substrate 1. This 3
As shown in FIG. 1, the two light receiving portions (N ⁻ type epitaxial layer 3) are formed on the semiconductor substrate 1 by a P ⁺ type element isolation diffusion region 2 b.
And the P ⁺ buried region 2a. Then, a positive voltage is applied N ^- -type epitaxial layer 3 cathode - and de region, whereas, P ⁺ buried region 2a
The grounded P ⁺ -type element isolation diffusion region 2b is used as an anode region, and the P ⁺ -type element isolation diffusion region 2b is formed to have a width of several μm adjacent thereto.

Using the light-receiving portion thus formed, the light radiated on the light-receiving surface is used as a photocurrent for each cathode electrode 5.
Then, the light intensity is detected through an amplifier circuit 6 formed on the same substrate as this semiconductor light receiving element. Reference numeral 4 in FIG. 1 denotes an N ⁺ -type electrode extraction diffusion region, and 9
Is an antireflection film.

In the CD pickup, it is necessary to input a voltage to the control circuit at the subsequent stage, and a current-voltage conversion amplifier circuit is used.

A feature of the integrated circuit device with a built-in light receiving element of the first embodiment is that the standard process for forming a transistor used in an integrated circuit is utilized and the N ^-- type epitaxial layer 3 is used.
Is formed at the same time when other transistors are formed by diffusing each P ⁺ -type element isolation diffusion region 2b to be an anode region of each light-receiving section and the P ⁺ -type buried region 2a of about 2 μm. There is a point that can be done. That is, the semiconductor light receiving element can be formed in the integrated circuit on the same substrate without adding an additional step to the standard process used for the integrated circuit.

The method for manufacturing the semiconductor light receiving element of the first embodiment will now be described. First, after each P ⁺ type buried region 2a is formed in the semiconductor substrate 1, the N ⁻ type epitaxial layer 3 is formed. After growing, the P ⁺ type element isolation region 2b is diffused, thereby dividing the N ⁻ type epitaxial layer 3.

Then, in order to connect the cathode electrode (wiring) 5 to each divided N ⁻ type epitaxial layer 3, N ⁺
After forming the die electrode lead-out diffusion region 4, an antireflection film 9 is formed, and then a contact hole for connecting the cathode electrode 5 is formed on the antireflection film 9 to form the cathode electrode ( Wiring) 5
Are formed to manufacture the semiconductor light receiving element of the integrated circuit device with a built-in light receiving element shown in FIG.

In the integrated circuit device with a built-in light receiving element according to the first embodiment described above, when the light receiving portion is irradiated with light and the generation of the carrier hole pair due to light absorption occurs below the P ⁺ buried region 2a. , Minority carriers will move in all directions due to diffusion. The electrons moving in all directions are P
Reaching the ⁺ type buried region 2a and the P ⁺ type element isolation diffusion region 2b, most of the carriers will be recombined with the holes.

The location where the carrier hole pair is generated by this light absorption varies depending on the material of the semiconductor element and the wavelength of the irradiated light. Therefore, the semiconductor light receiving element does not generate a photocurrent due to the carriers generated below the P ⁺ buried region 2a. Therefore, in the integrated circuit device with a built-in light receiving element of the first embodiment, the crosstalk between the light receiving portions can be greatly reduced.

(Embodiment 2) FIG. 2 is a sectional view of a semiconductor light receiving element showing another embodiment (embodiment 2) of an integrated circuit device with a light receiving element according to the present invention. In FIG. 2, 7 is an N ⁺ type element isolation diffusion region, and 8 is a P ⁺ type light absorption diffusion region. Other reference numerals 1, 3, 5 and 6 are the same as those in FIG. 1 described above.

In the semiconductor light receiving element of the integrated circuit device with a built-in light receiving element according to the second embodiment, the wavelength of the light emitting source is moving toward the short wavelength side as the recording density from CD to DVD increases.
The location where the carrier holes are generated by light absorption becomes narrower as the wavelength of the irradiated light becomes shorter. The second embodiment is a semiconductor light receiving element that utilizes this effect, and the "CD
The semiconductor light receiving element of the integrated circuit device with a built-in light receiving element used for the above.

The feature of the second embodiment is that the standard process for forming a transistor used in an integrated circuit is used as in the case of the first embodiment, and thus the standard process used in the integrated circuit is added. The semiconductor light receiving element can be formed in an integrated circuit on the same substrate without adding steps.

The method of manufacturing the semiconductor light receiving element shown in FIG. 2 of the second embodiment will be described. First, the N ⁻ type epitaxial layer 3 is thinly formed on the semiconductor substrate 1, and then,
An N ⁺ type element isolation diffusion region 7 is formed in order to capture minority carriers generated outside the light receiving region and to connect the cathode electrode 5. Next, a P ⁺ type light absorption / diffusion region 8 for connecting the light receiving region and the anode electrode is formed, an antireflection film 9 is formed, and then a contact hole for the anode electrode is formed in the antireflection film 9. And the wiring 5a for the anode electrode is formed to manufacture the semiconductor light receiving element of the integrated circuit device with a built-in light receiving element shown in FIG.

(Embodiment 3) FIG. 3 is a plan view showing an embodiment (Embodiment 3) in which the integrated circuit device with a built-in light receiving element according to the present invention is used for a CD or the like.

In the third embodiment, the light receiving element portion 11 and the integrated circuit portion 6a have the structure shown in FIG. 3, and are connected by aluminum wiring or the like. Further, the integrated circuit portion 6a and the light receiving element portion 11 are separated by an element isolation region (separation diffusion region of the light receiving element portion and the circuit portion) 10, and the portion other than the light receiving element portion 11 is shielded by aluminum or the like. Therefore, the light receiving element section 11
The light radiated on the light has an advantage that it does not affect the integrated circuit portion 6a. It should be noted that FIG. 4 shows the integrated circuit device with a built-in light receiving element of the third embodiment shown in FIG.
It is an element surface distribution diagram of the output voltage which measured the space.

[0035]

As described in detail above, the present invention uses the standard manufacturing process of an integrated circuit, so that the elements of the light receiving element can be easily separated and the elements can be miniaturized.
In addition, productivity can be improved without additional steps. The reason is that a high-concentration region of the same conductivity type is embedded in the semiconductor substrate, and the light-receiving element can be separated at the same time as the transistor is formed by diffusing the high-concentration region of the same conductivity type.

Further, according to the present invention, the sensitivity can be obtained without widening the depletion layer region in the light receiving region, and the voltage can be lowered (that is, the consumption voltage can be reduced). The reason is that the light receiving region is formed by thin epitaxial growth.

[Brief description of drawings]

FIG. 1 is a sectional view of a semiconductor light receiving element showing an embodiment (Example 1) of an integrated circuit device with a light receiving element according to the present invention.

FIG. 2 is a sectional view of a semiconductor light receiving element showing another embodiment (embodiment 2) of an integrated circuit device with a light receiving element according to the present invention.

FIG. 3 is a diagram showing the integrated circuit device with a built-in light receiving element according to the present invention as a CD.
The top view which shows one Example (Example 3) used for the etc.

4 is an element surface distribution diagram of the output voltage measured between AA in FIG. 3 in the integrated circuit device with a built-in light receiving element of Example 3 shown in FIG. 3;

FIG. 5 is a diagram illustrating a conventional semiconductor light receiving element,
(A) is the top view, (B) is the XX sectional view taken on the line of (A).

[Explanation of symbols]

1 Semiconductor Substrate 2a P ⁺ Type Embedded Region 2b P ⁺ Type Element Isolation Diffusion Region 3 N ^- Type Epitaxial Layer 4 N ⁺ Type Electrode Extraction Diffusion Region 5 Cathode Electrode 5a Wiring 6 Amplifier Circuit 6a Integrated Circuit Section 7 N ⁺ Type Element isolation diffusion region 8 P ⁺ type light absorption diffusion region 9 Antireflection film 10 Separation diffusion region of light receiving element portion and circuit portion 11 Light receiving element portion 12 Light receiving element portion 13 P-side electrode 13a electrode of light receiving element 14 Forming light receiving portion Diffusion region 15 Diffusion region forming depletion region including peripheral part 16 Antireflection film 17 n-side electrode 18 Non-doped InGaAs absorption layer (light absorption region) 19 n ⁺ type InP substrate

Claims (3)

[Claims] 1. A second conductivity type region is formed on a high concentration region of the first conductivity type formed on a semiconductor substrate of the first conductivity type forming an integrated circuit, and the second conductivity type region is formed. A high-concentration region of the first conductivity type is divided into a plurality of regions, and the second-conductivity type region is surrounded by the high-concentration region of the first conductivity type. An integrated circuit device with a built-in light-receiving element. 2. A region of the second conductivity type is formed on a high-concentration region of the first conductivity type formed on a semiconductor substrate of the first conductivity type forming an integrated circuit, and a light receiving region is formed in the first light receiving region. 2. An integrated circuit device with a built-in light-receiving element, characterized in that the light-receiving region is divided into two high-concentration regions of conductivity type, and the light-receiving region is formed by the high-concentration region of the first conductivity type. 3. A method for manufacturing an integrated circuit device with a built-in light receiving element, wherein an integrated circuit and a plurality of light receiving elements are formed adjacent to each other on a semiconductor substrate, and between the light receiving sections and between the adjacent integrated circuits and the light receiving sections. The method for manufacturing an integrated circuit device with a built-in light-receiving element is characterized in that the minority carriers diffused in all directions are suppressed by using a standard manufacturing process of the integrated circuit.