JP2609670B2 - Semiconductor chip for CCD linear sensor and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention relates to a semiconductor chip for a CCD linear sensor, in which a plurality of semiconductor chips are connected in series to form a solid-state imaging device, and a method for manufacturing the same. Regarding

(Prior Art) In a so-called multi-chip solid-state imaging device in which a plurality of semiconductor chips are arranged in series to constitute a solid-state imaging device as one solid-state imaging device, it is necessary to separate a semiconductor wafer into semiconductor chips.

Conventionally, this separation has been generally performed by rotating a blade provided in a dicing device, bringing this blade into contact with the semiconductor wafer from vertically above the semiconductor wafer, and cutting it into a predetermined size.

Therefore, as shown in FIG. 6, the element surface 3 on the surface of the semiconductor chip 1 on which the pixels 2 are formed and the other semiconductor chip 1 are formed.
The angle between the connection end face 4 and the connection end face is substantially right, and the facing connection end faces 4, 4 are arranged to be parallel to each other.

In addition, for example, as disclosed in Japanese Patent Application Laid-Open No. 61-231757, an angle formed between two end surfaces of a connection part of a semiconductor chip and an element surface on which a solid state element is mounted is less than 90 °. In addition, Japanese Patent Application Laid-Open No. 62-176157 proposes a method in which a groove for cutting is formed in a substrate before forming a sensor, and the substrate is cut at the position of the groove. There is.

(Problems to be Solved by the Invention) In order to make a good connection between the end faces 4, 4 of the connecting portion shown in FIG. 6, the accuracy of the unevenness of the surface of the end face 4 must be increased. As shown in Fig. 7, due to wear and roundness of the blade, along the inclination of the blade,
In general, it has been difficult to obtain a high-precision connection end face 4 such that an angle α between the element surface 2 and the connection end face 4 may become an obtuse angle.

If a highly accurate end face of the connecting portion is not obtained, the placement accuracy of the semiconductor chip 1 is deteriorated, and the distance L between the adjacent pixels 2 and 2 of both semiconductor chips 1 and 1 sandwiching this connecting portion is reduced. A big error will occur. This is because, particularly in a CCD linear sensor, by arranging this interval L to be equal to the interval of the pitch P (FIG. 5) between other adjacent pixels, the image is made uniform in this length direction. Because of the necessity, it is considered that the problem is not only a big problem but also becomes more and more serious with the advent of a device having a high resolution in the future.

Further, even if the accuracy of the unevenness of the surface of the connection portion end face 4 is obtained, the crushed portion 5 as shown in FIG.
Is generally difficult to prevent.

Therefore, not only the characteristic deterioration at the connection part, for example, the resolution deterioration may occur, but also the distance L between the adjacent pixels 2 and 2 of both semiconductor chips 1 and 1 may be different from each other as in the above. It is difficult to make the pitch P equal to the pitch P between adjacent pixels, and the crushed portion 5 may have a large effect on the pixels 2 formed near the connection portion end face 4. .

This is described in Japanese Patent Application Laid-Open Nos.
The structure disclosed in Japanese Patent Application Laid-Open No. 62-176157 is also considered to be substantially the same because it is considered that the cutting is essentially performed using a blade.

In view of the above, it is an object of the present invention to provide a semiconductor chip in which a crushed portion is not generated on an end face of a connection portion of a semiconductor chip, and semiconductor chips can be arranged with high accuracy, and a method of manufacturing the same. To do.

[Configuration of the invention]

(Means for Solving the Problems) In order to achieve the above object, a semiconductor chip according to the present invention is a semiconductor chip for a CCD linear sensor which comprises a plurality of semiconductor chips arranged in series to constitute a solid-state imaging device. An etched vertical portion extending vertically downward from the surface of a connection portion end face of the chip with another semiconductor chip to be aligned with the other semiconductor chip, and a dicing slope inclined inward and continuous with the etched vertical portion. In this manufacturing method, a groove portion having a linear shape in the longitudinal direction and a rectangular cross section in the longitudinal direction is formed by etching in a portion of the surface of the semiconductor wafer, which becomes a connection portion with another semiconductor chip when cut. The dicing blade is tilted and inserted into the groove while the lower end of the dicing blade is in contact with the vertical wall inside the groove. In addition to cutting the semiconductor wafer, the semiconductor wafer is cut in a direction perpendicular to the longitudinal direction to separate the semiconductor wafer into a plurality of semiconductor chips.

(Operation) In the semiconductor chip configured as described above, since the vertical portion extends vertically downward from the surface of the end face of the connecting portion and is formed by anisotropic etching such as dry etching, the dicing is performed. Generation of a crushed portion due to the above is prevented, and further, the vertical portion is formed with high accuracy without unevenness, and further, since the inclined portion is formed continuously with the vertical portion and inclined inward, the semiconductor chips are arranged. At this time, by preventing interference between the inclined portions and aligning the vertical portions, the arrangement can be performed with high accuracy.

(Example) Hereinafter, an example is described with reference to drawings.

In FIG. 1, pixels 2 are formed on an element surface 3 on the surface of a semiconductor chip 1. End surfaces 4 of connection portions with other semiconductor chips 1 at both ends in the length direction of the semiconductor chip 1.
Is a vertical portion 4a formed by dry etching or RIE with good anisotropy extending vertically downward from the surface, and the vertical portion 4a.
And an inclined portion 4b that is inclined in a direction away from the connection end face 4 of the inside, that is, the other adjacent semiconductor chip 1.

As described above, by forming the vertical portion 4a by etching with good anisotropy such as dry etching, the occurrence of a crushed portion due to dicing or the like is prevented, and the vertical portion 4a is formed with high accuracy without unevenness. In addition, by forming an inclined portion 4b which is continuous with the vertical portion 4a and is inclined inward, it is possible to prevent the inclined portions 4b from interfering with each other when the semiconductor chips 1 are arranged. .

When the semiconductor chips 1 are arranged in a line to form a solid-state image pickup device, the vertical portions 4a face each other in parallel, and moreover, between the adjacent pixels 2 and 2 of both the semiconductor chips 1 and 1. By matching so that the distance L is equal to the pitch P between the other adjacent pixels 2, 2 (FIG. 5), interference of the inclined portion 4b is prevented, and this arrangement is performed with high accuracy. You can

The length d of the vertical portion 4a should be set to be sufficiently larger than the variation of the thickness in consideration of the variation in the thickness of the semiconductor chips 1 adjacent to each other. It is desirable in order to surely prevent a step difference from being generated by polymerizing without facing each other.

That is, the variation in the thickness of this type of semiconductor chip 1 is
Usually, the length d is about 30 μm,
Is sufficiently larger than this value of 30 μm, for example, about 100 μm (d ≒ 100 μm).

A method of manufacturing the semiconductor chip 1 will be described with reference to FIGS. 2 to 5.

This semiconductor chip 1 is manufactured by cutting the semiconductor wafer 6. First, as shown in FIG. 2, a portion of the surface of the semiconductor wafer 6 which becomes a connection portion with another semiconductor chip 1 when cut. Further, the groove portions 6a, 6a having a straight line and a rectangular cross section are formed by dry etching, RIE or the like having good anisotropy. The depth d 'of the square groove 6a is, as described above,
For example, about 100 μm (d ′ ≒ 100 μm), at least 20 μm
And the width W is the following dicing grade 8
The width is set so as not to hinder the insertion into the inside of the groove 6a, for example, about 20 μm (W ≒ 20 μm).

In this way, the etching with good anisotropy ensures high precision, that is, the groove portion with very few irregularities in the vertical and horizontal portions.
6a and 6a are formed.

Next, as shown in FIG. 3, a CCD pattern 7 is formed on the surface of the semiconductor wafer 6 having the grooves 6a, 6a.

The dimensional relationship between the groove 6a and the CCD pattern 7 is as follows.
The pitch P between the pixels 2 and 2 (FIG. 5) is set to be equal to the distance L between the adjacent pixels 2 and 2 of both semiconductor chips 1 and 1 connected.

When the formation of the final CCD pattern 7 is completed, the fourth
As shown in the figure, the lower end of the dicing blade 8 contacts the vertical wall inside the groove 6a,
Is inserted into the groove 6a at an angle, and is cut by rotating.

At this time, the angle θ between the blade 8 and the horizontal plane is preferably less than 90 °, for example, 70 ° or more (70 ° ≦ θ <90 °).

Since the last separation of the semiconductor chips 1 does not require the accuracy of the end face of the connecting portion, as shown in FIG. 5, the dicing blade 8 is rotated as in the conventional case without forming a groove or the like. Thus, the semiconductor chips 1 shown in FIG. 1 are separated and formed, and the required number of semiconductor chips 1 are arranged in a line as shown in FIG. 1 to constitute a solid-state imaging device.

〔The invention's effect〕

Since the present invention has the above-described configuration, the end face of the connecting portion of the semiconductor chip is composed of a vertical portion having no crushed portion and high accuracy, and an inclined portion which is continuous with this vertical portion and is inclined inward. By aligning the parts, the semiconductor chips can be arranged with high accuracy. Therefore, by using this semiconductor chip, it is possible to improve the accuracy of the connection portion and configure a high-performance solid-state imaging device in which characteristic deterioration does not occur.

Further, according to the present manufacturing method, there is an effect that the semiconductor chip having the above-described effects can be relatively easily and reliably manufactured.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a connection portion of a semiconductor chip, FIGS. 2 to 5 show manufacturing steps of a semiconductor chip in the order of steps, FIG. 2 (a) is a plan view showing a state where a groove is formed in a semiconductor wafer,
FIG. 3B is a front view, FIG. 3 is a plan view showing a state in which a CCD pattern is formed, FIG. 4 is a front view showing a state of cutting along a groove, and FIG. 5 is separated into individual semiconductor chips. FIG. 6 is a perspective view showing a connection portion of a conventional semiconductor chip, and FIG. 7 is an enlarged front view showing a portion A in FIG. 1 ... semiconductor chip, 2 ... pixel, 3 ... element surface, 4 ...
... end face of connecting part, 4a ... vertical part, 4b ... inclined part, 6 ...
… Semiconductor wafer, 6a …… Same groove, 7 …… CCD pattern.

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01L 25/04 Z

Claims (2)

(57) [Claims] 1. A semiconductor device for a CCD linear sensor comprising a plurality of semiconductor chips arranged in series to constitute a solid-state imaging device, wherein an end face of a connection portion between the semiconductor chip and another semiconductor chip is vertically downward from the surface. A semiconductor chip for a CCD linear sensor, characterized in that it comprises an etching-formed vertical portion that extends to the other side and is aligned with another semiconductor chip, and a dicing-formed inclined portion that is continuous with the etching-formed vertical portion and is inclined inward. 2. A groove having a linear shape in a longitudinal direction and a rectangular cross section is formed in a portion of a surface of a semiconductor wafer, which becomes a connection portion with another semiconductor chip when cut, by etching, and dicing is performed inside the groove. While cutting the semiconductor wafer by inclining and inserting the dicing blade while abutting the lower end portion of the blade on the vertical wall inside the groove portion, cutting into a plurality of semiconductor chips by cutting in the direction orthogonal to the longitudinal direction. A method for manufacturing a semiconductor chip for a CCD linear sensor, comprising separating the semiconductor chip.