JPH0438838A - Charge-coupled element - Google Patents

Abstract

PURPOSE:To achieve high integration without increasing a chip area by extending a transfer electrode with a contact hole for making connection to a first-phase transfer clock wire to another in-phase transfer electrode without having the contact hole for forming in one piece. CONSTITUTION:Although transfer electrode pairs 1-1 and 1-2 of a first phase are connected to a transfer clock wire 5 by a contact hole 7. no contact hole is provided at in-phase transfer electrodes 2-1 and 2-2 and an opposite side from the contact hole 7 of the transfer electrode pairs 1-1 and 1-2 with the contact hole 7 is extended to the transfer electrodes 2-1 and 2-2 for achieving a one-piece and continuous formation. Also, second-phase transfer electrode pairs 3-1 and 3-2 and 4-1 and 4-2 are connected to a secondphase transfer clock wire 6 by the contact hole 7 each. Thus, since the contact hole is reduced by a pair of electrodes, the space is used to allow electrodes at a different potential to be arranged while maintaining a sufficient gap.

Description

[Detailed Description of the Invention] [Summary] Regarding the connection structure between the transfer electrode and clock wiring of a one-dimensional or two-dimensional charge-coupled device, especially a charge-coupled device, the design specifications of the transfer electrode are relaxed to prevent contact failure and between the electrodes. The aim is to reduce short-circuits in semiconductor substrates and achieve high integration, and to increase the width of the lead-out portion of the transfer electrode to reduce electrical resistance and enable high-speed charge transfer. In a charge-coupled device in which a plurality of transfer electrodes are arranged above with an insulating film interposed therebetween, a transfer electrode having a contact hole for connecting to the first phase transfer clock wiring is connected to another same-phase transfer electrode that does not have a contact hole. The transfer electrode is configured to extend and be integrally formed with the transfer electrode.

Further, at this time, the second phase transfer electrode is configured to bypass the contact hole of the first phase transfer electrode and extend with substantially the same radius.

[Industrial Field of Application] The present invention relates to a -dimensional or two-dimensional charge coupled device, and particularly to a connection structure between a transfer electrode of a charge coupled device and a clock wiring.

In recent years, solid-state imaging devices used in facsimile machines, copying machines, home-use color video cameras, and the like are required to have improved resolution.

To achieve this, it is necessary to increase the number of pixels within a predetermined design specification or area, but it is also necessary to increase the degree of integration of the region for transferring the charges generated by the pixels.

[Prior Art] In a charge transfer region of a conventional solid-state imaging device, each of a plurality of charge transfer electrodes is provided with a contact hole for connection to a transfer lock wiring of each phase.

FIG. 4 is a plan view of a charge coupled device of a conventional solid-state imaging device.

In this figure, 1-1.1-2 and 2-1.2-2
are the first phase transfer electrode pair, 3-1.3-2, and 4-1
．． 4-2 is a pair of transfer electrodes for the second phase, 5 is a first phase transfer lock wiring, 6 is a second phase transfer lock wiring, 7 is a contact hole, and 8 is a charge transfer path.

In this device, the first phase transfer electrode pair 1-1.1-
2 and 2-1.2-2 are connected to the first phase transfer lock wiring 5 and contact hole 7, respectively, and the second phase transfer electrode pairs 3-1.3-2 and 4-1.4 −
2 are connected to the second phase transfer lock wiring 6 through contact holes 7, respectively.

FIG. 5 is a cross-sectional view taken along the line c-c' in FIG. 4, and FIG. 6 is a cross-sectional view taken along the line D-D' in FIG. It shows.

The reference numerals in FIGS. 5 and 6 are the same as those described with the same reference numerals in FIG. 4.

These plural transfer electrodes 1-1.1-2.2-1.2-
The clock signal of the first phase (Φ1) as shown in FIG. 7 is transferred to the transfer electrode 3-1.3- through the lock wiring 5.
Transfer to 2.4-1.4-2 and pass through the lock wiring 6 to the second
When a phase (Φ) clock signal is applied, the internal potential under each electrode changes, and charges are transferred in the direction shown by the arrow in Figure 4 (.

[Problem to be solved by the invention]

In the conventional charge-coupled device described above, contact holes for transfer electrodes and wiring are provided in each electrode, making it difficult to miniaturize the transfer region.

Therefore, as the number of pixels increases, this becomes an impediment to the high integration of the entire imaging device.Reducing the distance between the transfer electrodes leads to short-circuits between the electrodes, and reducing the width of the lead-out portion of the transfer electrodes causes problems in this area. The electrical resistance increases, which impedes high-speed transfer and locking, and there is also the risk of wire breakage at this portion.

The present invention aims to solve these problems.

;Means for Solving the Problems] In a charge coupled device according to the present invention, in a charge coupled device in which a plurality of transfer electrodes are arranged on a semiconductor substrate with an insulating film interposed therebetween, a first phase transfer port is provided. A configuration is adopted in which a transfer electrode having a contact hole for connection to a wiring line extends and is integrally formed with another transfer electrode of the same phase that does not have a contact hole.

Furthermore, in this case, a configuration was adopted in which the second phase transfer electrode bypasses the contact hole of the first phase transfer electrode and extends with substantially the same width.

(Function) In the charge-coupled device of the present invention, the transfer electrode having a contact hole for connecting to the first phase transfer lock wiring extends to and is integrated with other same-phase transfer electrodes that do not have contact holes. The number of contact holes can be reduced as a whole.
This creates leeway in the design specifications.

Further, at this time, the second phase transfer electrode bypasses the contact hole of the first phase transfer electrode and extends with substantially the same width, so the electrical resistance of this portion becomes small.

〔Example〕

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

1 is a plan view of a charge-coupled device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA' in FIG. 1, and FIG. 3 is a sectional view taken along line AA' in FIG. 1. FIG.

The reference numerals in the figure are the same as those described using the same reference numerals in FIG.

In this embodiment, as shown in the drawing, the first phase transfer electrode pair 1-1.1-2 is connected to the transfer lock wiring 5 through the contact hole 7 as before, but the in-phase transfer electrode pair 1-1. No contact hole is provided in the transfer electrode 2-1.2-2, and the side opposite to the contact hole 7 of the transfer electrode pair 1-1.1-2 having the contact hole 7 is the transfer electrode 2-1.2-. 2 and is integrally and continuously formed.

In addition, electrode pairs 3-1.32 and 4 of the second phase transfer electrode
-1, 4-2 are individually connected to the second phase transfer lock wiring 6 through contact holes 7, as in the conventional element.

In this embodiment, since the number of contact holes is reduced by one pair of electrodes, the space can be used to arrange electrodes of different potentials with sufficient spacing between them.

Also, as mentioned above, we had more space, so we decided to
The width of the lead-out portion of the phase transfer electrode can be made wide and approximately equal to the width of the transfer electrode.

In the above embodiment, contact holes are arranged at every other electrode of the first phase, but they may be arranged at every plurality of electrodes.

Further, although this embodiment has been described as omitting the contact holes of the first phase transfer electrodes, it can also be applied to the second phase, or both the first phase and the second phase.

Further, in the above embodiment, the case of a two-phase clock was explained, but the present invention is not limited to this, and can also be applied to a case of a multi-phase clock other than two-phase.

(Effects of the Invention) In the present invention, since contact holes are arranged across at least one transfer electrode of the same phase,
The design specifications of the transfer electrodes can be relaxed, conventional problems such as short circuits between electrodes can be reduced, and high integration can be achieved without increasing the chip area.

Furthermore, the space created by omitting the contact hole can be used to make the electrode width wider than before, which reduces electrical resistance, allowing the transfer lock waveform to be transmitted without distortion and allowing charge to be transferred at high speed. This makes it possible to completely eliminate disconnection of the transfer electrodes.

Furthermore, since the contact hole can be made larger, electrical contact failures are reduced.

In the conventional example shown in Fig. 4, the lateral size of the contact hole is N, the margin between the contact hole and the polysilicon transfer electrode is A, the width of the polysilicon transfer electrode is W, and the gap between the polysilicon transfer electrodes. is G, and the number of transfer electrode pairs is M, then the length L of the charge coupled device in the charge transfer direction is
For A, LA=M (N+2A+-20+W).

Next, the length Lll of the charge-coupled device when all the transfer electrodes of the same phase are connected and only one contact hole with the Cronk wiring is provided is Ll=M (2G+2W)=2
M (C; +W).

The difference ΔL between the two is ΔL=LA−Ll=M (N+2A−W), and since normally N+2A>W, it is possible to reduce the chip size of the charge coupled device by as much as ΔL.

In other words, it is possible to increase the number of pixels and the number of transfer electrode pairs of the charge transfer element without increasing the chip size, and the resolution can be improved.

[Brief explanation of drawings]

FIG. 1 is a plan view of a charge-coupled device according to an embodiment of the present invention, and FIG.
The figure is a sectional view taken along the line AA' of the embodiment of the present invention.
The figure is a sectional view taken along the line BB' of the embodiment of the present invention.
FIG. 5 is a cross-sectional view of the conventional charge-coupled device taken along line C-C, FIG. 6 is a cross-sectional view of the conventional charge-coupled device taken along line D-D', and FIG. The figure shows the transfer lock signal. In the figure, 1-1.1-2.2-1.2-2.3-1.3-
2.4-1.4-2 is a transfer electrode pair, 5 is a first phase transfer lock wiring, 6 is a second phase transfer lock wiring, 7 is a contact hole, and 8 is a charge transfer path.

Claims (2)

[Claims] (1) In a charge-coupled device in which a plurality of transfer electrodes are arranged on a semiconductor substrate with an insulating film interposed therebetween, a transfer electrode having a contact hole for connecting to a first phase transfer clock wiring has a contact hole. 1. A charge-coupled device comprising a structure that extends to and integrally forms other in-phase transfer electrodes that do not have a charge-coupled device. (2) In claim 1, the second phase transfer electrode is the first phase transfer electrode.
A charge-coupled device characterized in that the charge-coupled device comprises a configuration in which the contact holes of the phase transfer electrodes are bypassed and extend with substantially the same width.