JP2924482B2 - Semiconductor integrated circuit device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor integrated circuit device having a redundant circuit, and more particularly to a semiconductor integrated circuit device using a fuse element which is blown by laser irradiation as a PROM element for switching use of the redundant circuit.

[0002]

2. Description of the Related Art In a semiconductor integrated circuit device, a fuse element which has a redundant circuit and is blown by laser irradiation to replace a defective memory cell with a redundant memory cell is generally provided. As shown in FIG. 3, such a fuse element has a pair of electrodes (metal wiring layers 4-1 and 4-) on both ends of a polysilicon film 1 or the like that selectively covers a predetermined interlayer insulating film of a semiconductor chip. 2) is provided, and after testing the semiconductor integrated circuit device and investigating the position of the defective memory cell and the number of defective memory cells, if redundant memory cells are used, it is suitable when all the memory cells become non-defective. Such a fuse element is irradiated with a laser beam and blown, and a defective address is replaced with a redundant address, and data can be written to and read from a redundant memory cell.

As described above, a method of increasing the production yield by using a method of testing a semiconductor integrated circuit device and replacing a defective memory cell with a redundant memory cell is generally performed. In particular, with the increase in the capacity of the memory cells, the probability that all the memory cells can be formed without a defect decreases, and the method of providing redundant memory cells in a semiconductor integrated circuit device has become common in view of the problem of minute dust on a manufacturing line. .

[0004]

The fuse element for use of the conventional redundant circuit is provided only in the semiconductor integrated circuit device. If the irradiation position of the laser beam for cutting the fuse element is changed. deviation, there is no way to check even without the original cutting all-out fuse element is disconnected,
If the fuse element is cut correctly, there is a problem that a non-defective semiconductor integrated circuit device becomes defective.

[0005]

According to the present invention, a pair of electrodes are provided at both ends of a first conductive film selectively deposited on a predetermined interlayer insulating film of a semiconductor chip . Part
Cover with a protective film with an opening for laser beam irradiation
In a semiconductor integrated circuit device provided with a redundant circuit having a covered fuse element, a second conductive film provided adjacent to a first conductive film of the fuse element and both ends of the second conductive film are provided. And a pair of provided probing pads.

[0006]

Referring to FIG. 1, in a first embodiment of the present invention, a plurality of fuse elements (thickness 0.3 μm, width 1.0 μm) are used.
It is made up of a stripe-shaped polysilicon film m, 4.0 μm long, and metal wiring layers 4-1 and 4-2 connected to both ends thereof. ) Are provided at a pitch of 4.0 μm, and a polysilicon film 5 having a thickness of 0.3 μm and a width of 1.0 μm is provided meandering between the polysilicon films 1. Probing pads 6 and 7 are connected to both ends of the polysilicon film 5.

The semiconductor integrated circuit device is electrically tested to investigate the number of defective memory cells and their locations, and to fuse the polysilicon film 1 of a suitable fuse element with a laser to switch a defective address to a redundant circuit. By doing so, the defective memory cells are replaced with redundant memory cells. 2
Means that the polysilicon film 1 is easily blown by laser irradiation at an opening provided in an interlayer insulating film deposited after providing the polysilicon film 1 and a protective film covering the metal connection layers 4-1 and 4-2. It is provided for. Reference numeral 3 denotes a through hole which is opened to connect the polysilicon film 1 to the metal wiring layers 4-1 and 4-2. The metal wiring layers 4-1 and 4-2 are connected to a redundant circuit (not shown). At this time, even if the irradiation position of the laser beam is shifted, for example, the laser beam is irradiated between the polysilicon films 1 of the two adjacent fuse elements and the fuse element which should be cut is not blown, the polysilicon film 5 may be cut. Is blown, it is possible to examine the presence / absence of the displacement of the laser beam irradiation by applying a voltage between the probing pads 6 and 7 electrically. If the space between the probing pads 6 and 7 is open, the laser beam is misaligned and the polysilicon film 5 is blown. Therefore, the laser beam is again positioned, and the fuse is cut by irradiating the laser beam again. Just do it. The probing pads 6 and 7 are provided with openings 8-6 and 8-7 in the protective film, respectively.

FIG. 2 is a plan view showing a second embodiment of the present invention, in which a sensing element comprising a polysilicon film 5 and probing pads 6 and 7 is provided on both sides of each fuse element. If any one of the probing pads of the sensing elements on both sides of one fuse element is open, it means that one of the fuse elements on both sides is not blown. There is an advantage that the accuracy is good.

[0009]

As described above, according to the present invention, the second conductive film is disposed adjacent to the programming fuse element for replacing a defective memory cell with a redundant memory cell, and the electrical conduction on both sides thereof is checked. In this way, it is possible to find a replacement failure due to a displacement of the laser beam when the fuse element is blown, and to perform the replacement correctly by irradiating the laser beam again, thereby improving the yield of the semiconductor integrated circuit device with the redundant circuit. Have.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing a first embodiment of the present invention.

FIG. 2 is a plan view schematically showing a second embodiment of the present invention.

FIG. 3 is a plan view schematically showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polysilicon film 2 Opening 3 Through hole 4-1 and 4-2 Metal wiring layer 5 Polysilicon film 6,7 Probing pad 8-6,8-7 Opening

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 27/102 H01L 21/66 H01L 21/82 H01L 27/10

Claims (1)

(57) [Claims] 1. A pair of electrodes are provided at both ends of a first conductive film selectively applied to a predetermined interlayer insulating film of a semiconductor chip, and a portion of the first conductive film is irradiated with a laser beam.
In the semiconductor integrated circuit device having a redundant circuit having a fuse element which is covered with a protective film having an opening for the second conductive film provided adjacent to the first conductive film of said fuse element, said first 2. A semiconductor integrated circuit device comprising: a pair of probing pads provided at both ends of two conductive films.