JPS5963777A - Manufacturing method of silicon photodiode device - Google Patents

Abstract

PURPOSE:To obtain the diode, in which a plurality of photodiodes are separated excellently, by implanting impurity ions, changing the conduction type of an impurity and forming a junction region when a plurality of the photodiodes are formed adjoined onto the same substrate. CONSTITUTION:The N type Si substrate 1 of resistivity of at least 1KOMEGA.cm or more is prepared, neutron beams are radiated to a plurality of predetermined regions, and N type regions 21 and 22 are formed through annealing. Electrodes 41 and 44 are set up to these regions, P type ions are implanted into the regions 21 and 22, the surface is annealed by beams, P type ions compensate for N type ions decayed by neutron beams, and P type regions 31 and 32 are formed. Electrodes 42 and 42 are set up to the regions 31 and 32, and a pluraity of the photodiodes are obtained adjoined onto the substrate. Accordingly, diode groups are separated excellently.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a silicon photodiode device in which two or more photodiodes are formed on the same silicon substrate -1-.

Another conductive layer is provided by ion implantation or diffusion of an impurity to impart other conductivity to two or more locations on one surface of a conventional one-conductivity silicon substrate of the above type.
An L-N junction is formed.

In the silicon diode device formed by the above method, there is a problem in that crosstalk J: or coupling between adjacent photodiodes is only η2.

In other words, when light enters one of the photodiodes, some of the carriers from the light η may move to other photodiodes, making it difficult to accurately calculate the amount of light incident on each photodiode. Undetectable.

This problem can be solved by increasing the distance between photodiodes on the same silicon substrate. However, as the degree of integration of the photodiode device is reduced, it is necessary to form an insulating layer between the photodiodes.
Separation methods such as providing kerfs have been proposed and implemented.

An object of the present invention is to provide two or more po-diodes in close proximity on the same silicon substrate in a completely different manner from the above proposals.
An object of the present invention is to provide a method for manufacturing a silicon photodiode device.

In order to achieve the above-mentioned object, the present invention provides a silicon substrate 1.
~ A method for manufacturing a diode device is a method for manufacturing a silicon board diode device in which two or more photodiodes are formed on the same silicon W board, in which a high-resistance silicon substrate is irradiated with a neutron beam to determine the mass number in the silicon substrate. a step of converting a part of silicon having a mass number of 30 to phosphorus having a mass number of 31; a step of implanting a P-type impurity into two or more adjacent parts of one surface of the substrate; The method includes an annealing step of irradiating light onto the All-injected regions including the implanted portions thereof to anneal the regions beyond the depth of the P-type impurity ion implantation.

That is, in the method of the present invention, when a high-resistance silicon substrate is irradiated with a neutron beam, the neutrons undergo a nuclear reaction with silicon having a mass number of 30 in the substrate, and silicon having a mass number of 31 is generated.

Silicon, which has a mass number of 31, has a half-life of 2.62 hours and decays into phosphorus, which has a mass number of 31, while emitting heta rays. This phosphorus having a mass number of 31 acts as an N-type impurity in the silicon substrate.

However, the phosphorus produced in silicon in this way is inactive and its crystals are disordered.

Therefore, in this state, the silicon substrate maintains its insulating properties.

Gono Siri]rnnnol! ;Ion type I) impurity on one side of the plate1. Enter the light and enjoy the light (when you irradiate it, the silicon substrate is irradiated).Is this part of the part? iti O'＜L,
Danora exhibits P-type exclusiveness, and the other parts are insulated.

In addition, 1j; Teru mentioned in 1! The irradiated light with I=J is 11 (converted into heat in the plate and contributes to annealing,
YAGL-Li, key 1. -It must be a powerful light such as a non-solar lamp.

It is not annealed by the level of lighting that would be expected in a moderately cool human living environment.

Hereinafter, the present invention will be further explained with reference to the drawings and the like.

FIG. 1 is an old Jji plane view of a silicon photodiode-1 device manufactured in this way, and FIG. 2 is a plan view.

In each figure, the area indicated by the number I, the insulation of the substrate>Is
I finished 1st year of junior high school) 1 no Teru! 14, but is a high resistance region that has not been annealed by light.

The N-type conductive portions 21 and 22 are portions that are irradiated with neutron beams and then annealed with light to provide N-type conductivity.

N-type conductive portion 21. '22 is connected to electrodes 41 and 44, respectively.

I) type conductive layers 31 and 32 are irradiated with neutron beams, P type impurities are ion-implanted, and then annealed with light and phosphorus destroyed by the neutron beams and ■) type impurities compensated by ion implantation. In addition, the remaining P-type impurities give the portion P-type conductivity.

Electrodes 42.43 are connected to the P-type conductive layers 31.32, respectively.

A first silicon diode P-N junction is formed between the P-type conductive layer 31 and the N-type exclusive portion 21, and the P-type conductive layer 32
A 1) 7 N junction of a second silicon diode is formed between and N-type conductive portion 22 .

Next, an embodiment of the method for manufacturing the silicon photodiode device will be described with reference to FIGS.

FIG. 3 is a flowchart showing the manufacturing process, and FIG. 4 is an explanatory diagram showing the mask used in the manufacturing step T being treated with a silicon boron-diode-1 device.

(1)・Imi', at least the specific resistance is I KΩ・C1
Prepare 11 or more N-type layers, recon layers, and Z-type layers.

The thickness of this N-type silicon wethore is 35011 m.

(2) Illuminate the N-type silicon wafer with a neutron beam! 1・
]do.

After the irradiation, the solenoid wafer is left for several days to sufficiently attenuate the radiation of gamma rays and heta rays generated during nuclear transmutation caused by the neutron irradiation.

(j()) The two P-type layers 31.3 shown in the 41st No. 1Δ
A mask having an opening [ ] corresponding to the outer shape of No. 2 is placed on one surface of the silicon wafer.

(4) Boron ions are implanted from the mask side.

The energy of the implanted ions is 25 Kev, and the implantation amount L; l
: 10”/c+I+.

(5) Remove the mask shown in FIG.
A mask having an opening corresponding to the outer shape of the two N-type i2L 22 shown in fl B is placed on one surface of the silicon wafer. Between these two openings is lOμrn
An opaque part is provided.

(6) Irradiate G laser light to Y from the mask side. The output of the YAG radar is 1.3W, and the laser beam is focused to a diameter of 100μm and illuminates a silicon wafer at a distance of 20cm/
sec.

By this scanning, the aperture is 7 times removed.

Then, N
A P-type conductive portion is formed, and a P-type layer is formed in the center of the N-type conductive portion to a depth of 0.24 μrn.

(7) Next, the P-type conductive IFi formed as described above
Electrodes 42, 43 are formed on the surfaces of 31, 32, and electrodes 41, 44 are formed on the surfaces of the N-type conductive portion 21, 22.

FIG. 5 shows the results of measuring the spectral sensitivity of the silicon photodiode device manufactured through the above steps.

From this graph, it can be seen that the silicon photodiode device has 4
It can be understood that the sensitivity is from 00nm to 1000nrn.

i1r' L/ < As explained above, according to the method of manufacturing a silicon photodiode-1 device according to the present invention, a silicon photodiode of 21u J- is placed on the same ='J4&J'! It can be formed in a state where br is divided by 1ζ11.

7, the invention was made by J. Silicon Bot. 1. The diode device is the same, Ill, two or more silicon in the diode; I',
Since the I-diode is formed in a well-circulated state, it can be expected to have a wide range of applications such as position detection.

The manufacturing method described in detail above can be modified within the scope of the present invention.

In the P-type impurity implantation step of the method described above, 1) the part where the ion merging of the type impurity was made was the part close to the phase 7j within the same surface of the substrate; It is also possible to use a silicon wafer with a thickness that is at least twice as thick as the substrate used in the method of the embodiment described above, and to form silicon photodiodes 1 on both sides of the substrate. .

[Brief explanation of drawings]

11th X+ 4;1 Silicone photodiode manufactured by the method according to the present invention1. A vertical cross-sectional view of the device, and FIG. 2 is a plan view. FIG. 3 is a flowchart showing the manufacturing process, and FIG. 4 is an explanatory diagram showing masks used in the manufacturing process in correspondence with a silicon photodiode device. FIG. 5 is a graph showing the spectral sensitivity of a silicon photodiode device manufactured by the method according to the invention. 1... High resistance region 21.22... N-type conductive portion 31.32... P-type conductive layer 41.42, 43.44... Electrode patent applicant Hamamatsu Television Co., Ltd. agent Patent attorney I] Ro Hisashi 2.1 Figure 3 Sai 4 Figure

Claims (1)

[Claims] (1) In a method for manufacturing a silicon photodiode device in which two or more POI diodes are formed on the same silicon substrate, a high resistance silicon substrate is irradiated with a neutron beam. Then, some of the silicon ions with a mass number of 30 in the silicon substrate are converted to 7
(The step of converting into phosphorus in Placement 31 and the above),! , I) type impurity is implanted into two or more adjacent parts of the surface of the 1 type impurity. ' , 5 open 1 (
Sa11. ) Irradiating light to this region to anneal it beyond the depth where the I) type impurity ions were implanted. (2) The silicon substrate has at least LL low resistance IKΩ・Cnl.
The silicon according to claim 1, which functions as an insulator to separate two or more silicon diodes 1 formed on the same substrate in the following N-type silicon wafer. A method for manufacturing a photodiode device. (3) The silicon according to claim 1, wherein the impurity implanted in the l) type impurity implantation step is a (III element):
1. Method for manufacturing a photodiode device. (4) The method for manufacturing a silicon photodiode-1" device according to claim 1, wherein the light used in the annealing step is YAG laser light. (5) P-type impurity is added in the P-type impurity implantation step. 2. The method of manufacturing a silicon photodiode device according to claim 1, wherein the two or more portions into which ions are implanted are portions adjacent to each other on the same surface of the substrate.