JPS6074475A - Solid state image pickup element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to a charge transfer device that transfers a signal charge obtained by receiving light in a fixed direction and generates an imaging signal. , the structure is like this
1. Regarding the left solid-state image sensor.

BACKGROUND TECHNOLOGY AND PROBLEMS A charge-coupled device (hereinafter referred to as CCD) is constructed using a 11L load Ilv, 4, and 4 mm, and a solid-state image sensor with t' is as follows: Broadly speaking, there are two types: frame transfer type and ink-line transfer type.
ing.

For example, an example of interline transfer type CCI) imaging 7 is as shown in Figure 1 of the drawings.
1. Arranged to form horizontal rows and vertical rows. Multiple ukes:
) 'e Vertical i of the element part / and the light receiving element part / (formed by multiple rows of CCD fl\ arranged along the j 1111 center σ) 1. Tadare 1i! i ql, <light reception/reduction 1 comprising <transmission section flooding
1 Go transfer section 3 and this light receiving/vertical transfer section, ? It is composed of a horizontal transmitter, an output section S, and a horizontal transmitter connected to the receiver. An active region is formed in which charge is transferred both vertically and horizontally.

When such an imaging device performs an imaging operation, a predetermined vertical transfer drive signal and horizontal transfer drive signal are supplied to the vertical α transfer unit S and horizontal transfer unit G, respectively, and a charge transfer operation is performed. In that case, for example, the signal charge obtained in each light receiving element section / by light reception within the /frame period is read out to the vertical transfer section -, and this is transferred to each horizontal blanking section by the charge transfer operation of the vertical transfer section i. The vertical 11T transfer to the horizontal transfer section is completed sequentially in each period. In this horizontal transfer section, the signal charge is obtained in the horizontal column of the receiving section 9'6.
．． The horizontal transfer of each signal charge to the output section 3 is completed in each horizontal video period by the charge transfer operation of the horizontal transfer section k, and an imaging output signal is obtained from the Ilj output section k.

More specifically, as shown in FIG. B is formed into the awn, and around each light-receiving element part/awn is a chiyannel 7. Tosonog-7 is completely formed. In addition, an overflow drain g is arranged adjacent to the channel 7, and this overflow drain g
There is a channel between yt++ and the adjacent vertical transfer yt++, 2.
Stopper 9 makes one difference. In the vertical transfer section 2, overlapping transfer electrodes 10 extending in the horizontal direction are sequentially arranged in the vertical direction with an insulating layer interposed therebetween. The vertical transfer part (11i10 is the first electrode) φ/ and the electrode φ- of the first electrode are arranged in the father force and have a shape of 1 σ, 01
．． The electrode φ/ and the first electrode φ2 are respectively the storage electrode φ/. and φyu. and transfer section electrode (potential barrier electrode) φ/
L and φyt are configured σ'i1. ing. And then 1
[in the transfer section]] The charge transfer operation is performed using the first electrode φ/
For example, a phase transfer 1 drive signal is supplied to the second electrode φa and the second electrode φa, and at that time, the storage section' electrode φ
/.

The storage region in the vertical transfer section Y is formed below the transfer section electrode φ/ and φ2c, and the transfer region (potential barrier region) in the vertical transfer section S is formed below the transfer section electrode φ/ and φ2L. For example, an ion implantation region 1 is not provided in the transfer region because the stain level is shallower (lower) than in the adjacent storage region and forms an electric charge to γ barrier.
．． Alternatively, the thickness of the insulating layer below the transfer section electrode φ/Uφ may be increased or the thickness of the underlying insulating layer may be increased. FIG. 2 13 shows a cross section of 13-II B in FIG.
The dimensions of the above-mentioned receiving section, the vertical transfer section and the overflow train G, the N-type semiconductor region and E7,
Channel stoppers 7 and 9 are respectively formed as P-type conductor regions with increased impurity concentration, and a first region in which 70 vertical transfer electrodes are formed via 72 insulating layers; Pole φノ is placed. In this example, the vertical transfer 7[j, pole also serves as the readout gate electrode A], and the readout gate part B also has this third electrode φ) (Details V
This is the accumulation\SIS electrode φ. ) are distributed.

In such a conventional solid-state image sensing device, an active region consisting of a light receiving/vertical transfer section 3 and a horizontal transfer section 3 formed on a P-type semiconductor substrate is surrounded by a σ In addition, the active area receiver) Y-/vertical 111 transfer section 3 and 11''
Since the impurity concentration of the P-type ``1'' body substrate // extending between the blade part S is increased, a P-type semiconductor region having an impurity concentration of 17ξ1 is formed. The channel stop region, which takes a low potential, is designed to prevent charges (electrons) generated in the active region from flowing into the active region. When it flows into a certain area, it becomes (1
%Rasai1. This is because there is a risk that the noise IJk may be mixed with the signal charge transferred and may be transferred, causing noise IJk in the image pickup output signal taken out from the output section S.

However, a double bracket 1:' is formed around the IJ11 region a'11. Channel stop area U
, the surface area of which becomes relatively important is t'l-1 and 1c) When incident light reaches the semiconductor substrate from the channel stop region and becomes
'1. A charge is generated by the conversion, and this charge spreads through the 1' conductor substrate, but some of it enters the 1 internal region from the P-type 31' conductor substrate as an unnecessary charge. 1 to 3, the channel around the LC2 active region [... is generated by photoelectric conversion based on the incident light from the stop region, and the active region 1 from the semiconductor substrate is generated.
Unnecessary charges entering the region mix with signal charges within the active region and are transferred, resulting in the inconvenience of producing noise components in the imaging output signal taken out from the output section.

Purpose of the Invention In view of the above, the present invention provides an active region on a semiconductor substrate, which generates signal charges by receiving light and transfers all the obtained signal charges in a predetermined direction, and a channel stop region is formed around the active region. Te form h + i Sane, Ru composition? Even if charges are generated by photoelectric conversion based on light incident on the channel stop region, such charges are prevented from diffusing in the semiconductor substrate and entering the active region as unnecessary charges. It is an object of the present invention to provide a solid-state statuary element capable of producing f[-.

Summary of the Invention A solid-state image sensor according to the present invention has a first conductivity type, for example,
On a P-type semiconductor substrate, a signal charge is generated by light reception and the obtained signal charge is transferred in a predetermined charge transfer direction.
J) A second semiconductor region having a conductivity type different from the first conductivity type is arranged between each of the first and second semiconductor regions. The conductivity type, for example, P type, ? A semiconductor region having the same conductivity type as the third semiconductor region and a third semiconductor region having a high impurity concentration are arranged along the first and third semiconductor regions, respectively. Handed out, these are the 1st, 1st, 1st, ? 95, a predetermined voltage fl-j may be applied to the third and third semiconductor regions (C).
Naσ) Go up.

By cutting in this way, a shape of 6 is formed around the occupied area.
9. People in the father σ channel stop area. Even if charges are generated by photoelectric conversion in response to r-r light, the generated charges are attracted to the third semiconductor region, which has a higher potential than the ratio of 1, and is transferred to the awn with a higher potential. 7. (Assuming that C diffuses through the semiconductor substrate and almost never flows from the semiconductor substrate into the active region) 1. Ru.

Embodiment FIG. 3 shows an example of the solid-state image sensor according to the present invention.
In this example, for example, in a P-type semiconductor substrate,
Active groups 1 and 0 are arranged so as to generate signal charges upon reception of light and to transfer the obtained signal charges in a predetermined charge transfer direction. This active region, 2
0 is a light receiving/vertical transfer section 3 comprising a plurality of light receiving element sections/and a plane transfer section 2 similar to those shown in Fig. 1.
, and the horizontal transfer section DA has the form FJy,a;n, and furthermore, this active region has -4
71. is shown in FIG. A similar output section 5 is provided. The active region; 20 generates signal charges at each light-receiving element section in the active region; Then, the horizontal transfer section transfers [1, to the adjacent output section S in the horizontal direction.

Surrounding the active regions 0 and 1''A blade portions, for example, a P-type conductor region obtained by increasing the impurity concentration of a semiconductor diode of type ■゛゛゛〈 which surrounds these active regions adjacently. Similarly, a P-type semiconductor surrounds the awn with a predetermined distance between it and the awn 2/ is formed. The P-type semiconductor region aa obtained by increasing the impurity concentration of the substrate is formed according to the formation formula No. 1. I'm here.

That is, the active region, , 20 and the output section, S-fil: ,
i P-type semiconductor regions λ/ and β with impurity concentrations
-V is therefore surrounded by flood weight σ, and between the P-type semiconductor region, , 2/ and Il, d, 1'': i is a semiconductor region of a different conductive shape, an N-type semiconductor region,...!3 with a relatively thick area S. 1', i next to the inner edge of this N-type semiconductor region 3 and the outer edge of P-type semiconductor region 2/
An N-type semiconductor region with a higher impurity concentration than 23 and a high impurity concentration N-type semiconductor region (hereinafter referred to as [.
, N1-type semiconductor region), 24 are arranged. N1-type semiconductor region, 2/1. 1. surrounds the active region θ and 13 force part k and goes around the active region 1. It also extends to the lower part and is broken.

Evening figure A, 1-jth, ? Figure Ill A-IV A
On one surface side of the P-type semiconductor substrate, adjacent to the outer edge of the double active region, 20, -
Two series of P-shaped IL conductor areas-! /2 anti-4-type semiconductor region flooding, N-type semiconductor region 23 and P-type semiconductor region, 2.
It can be seen that 2 is formed sequentially.

2. The P-type semiconductor region dl arranged in this way;
2. N-type semiconductor region? and N-decade semiconductor region j.
2/l: is an N-shaped barrel region 2 which collectively forms a channel stop region for the active region aθ.
During operation, a predetermined voltage I:E is applied to t1.3 and N1 type semiconductor regions. The awn is shaped like a tree.

Therefore, during operation, each region 2/, 2.2, . ．． 1.3 and 2
The potential of /l- is shown in FIG. 9 and 13 in relation to FIG. The potential force of the P-type semiconductor region located at the innermost end, 2/, and the P-type semiconductor region located at the outermost part, 2.2, is also low, and the electric potential f)/ of the N-type semiconductor region 23 is low. is higher than the potential of the P-type semiconductor region 1.ilj, 2/ and dl, and the potential of the KF-type semiconductor region 2t/, which becomes even higher. 3. This 1. Therefore, when P-type ′″1 is placed in the conductor region/j:
・Equation 2, where the channel stop action takes place, are each area forming the channel stop region, 2/:
l:, 1. , ), 3 and d, the light enters each region, and the human body is 1 time in each region,! /,! Approved.

23 and 3 from 2 to 1 (■) shaped semiconductor substrate.
If H11 is reached and charge (duplex) deficiency is generated by the element's conversion, will this happen? (i, the load is an N type 2F with a high potential spreading with 'i'
The conductor region 1 or 3 is effectively attracted) 1), and the higher 'ff, Ij, 7) 1) N1 type semiconductor region,
2 Z +/im gather I', ■] form ゛l'j,
'7: The dormant substrate // does not dissipate (7), therefore, each region: , l/, 22., ! The electric charge (electron) is P-type At/.

This prevents unnecessary electrons from entering the active region 20 from the conductive substrate.

In addition, the solid-state image sensing device related to the unexploded f4Jl is the j? ? The lJ type is not 1jiii% more similar to the above example.

As is clear from the explanatory power that exceeds the effect of the invention, according to the solid-state imaging device according to the present invention, the phenomenon occurs when light enters the channel stop region formed around the active region.
This prevents the charge from diffusing into the semiconductor substrate and entering the active region as unnecessary charge, so that the charge due to the light incident on the channel/transmission region becomes the signal charge.
Therefore, it is possible to always obtain a good imaging l''-1'' force signal with less noise components.

It also prevents the diffusion of charges in the semiconductor substrate due to light incident on the channel stop region 11-. In order to concentrate such charges, a conductor 1. which is different from the semiconductor body and which extends over a relatively large area in the channel stop region is used. Since the semiconductor region having the shape of the TV and the adjacent semiconductor region having the conductivity type 1 which is different from that of the semiconductor body and having the concentration of the 3I/object, have the structure 7'L, Charges caused by incident light are very effectively attracted and concentrated in these 1' conductor regions.

[Brief explanation of the drawing]

Figure 1 shows an image sensor with an incl line transfer type CC (1 & 1 schematic structure showing all examples of Fi images), Figure dA shows an image sensor with σ'I''l as shown in Figure 1. 1<1 ~ minute enlarged partial view, 4 Figure 13 (1 If B-If of Figure 1 A)
B Cross-sectional view at ItC, -f+1. l'r show 11! 'J schematic diagram y, Figure A is a cross-sectional view of IV A-1 to jΔ in Figure 3, and Figure 113 is a water type 29. For example! ml, 'I l' + weak, clear diagram. In the figure, 3 ("receiving ° C / weight i!" T transfer part, 11. (bow horizontal 11, sending part, tide is 1/1 force part, // is 4 and a half of P type)]
, body f1 (body, so θ what l occupied area 5.2/and 2.2
is P-form, '1' 1-body chain 1・Problem 1. ;;362N-type semiconductor region 1.2 is the N-type-'4LH,v, body region 3゜Representative Patent attorney 1 Keiaki Kanbara,'.

Claims (1)

[Claims] An active region is formed on the semiconductor substrate of the first conductivity type to generate signal charges by receiving light and to transfer the obtained signal charges in a predetermined charge transfer direction.
First and first semiconductor regions having a first conductivity type are arranged in a double manner around the first conductivity type, and between each of the first and first semiconductor regions, a conductivity type different from the first conductivity type is arranged. A third semiconductor region having a first conductivity type and a third semiconductor region having a first conductivity type having a higher concentration of cine obtuse than the third semiconductor region, respectively. 1. 1. above. A channel stop region is formed by the a-th, third and g-th semiconductor regions t''L, and a predetermined voltage is applied to the third and g-th semiconductor regions according to formula 7''1. solid-state image sensor.