JPS58207665A - Semiconductor device - Google Patents

Abstract

PURPOSE:To fuse away wiring layers with a low power by forming a recess having the inclined surface at the surface of semiconductor substrate, extending wiring layer crossing said recess, and melting away the wiring layer with a heating means and by fusing away it through flowing along the inclined surface. CONSTITUTION:A wiring layer 16 is formed in such a way as extending along the inclined surface of a recess 12 crossing it formed at the surface of semiconductor substrate. When it is judged that a defect is generated in the circuit by test, it is requested to irradiate a laser beam of comparatively low power, for example, with an energy of 0.3muJ to a part of wiring layer 16 located on the inclined surface for 200ns. Thereby, the wiring layer 16 partly fuses and flows along the inclined surface 17 and is disconnected. Thereby, a redundancy circuit operates. When the angle of inclined surface 17 is too gentle, the fused wiring layer 16 does not flow, while when it is too steep, the disconnection at the stepped portion occurs at the wiring layer 16.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a semiconductor device, and particularly to a semiconductor device equipped with a redundant circuit.

(Technical Background of the Invention) A semiconductor device shown in FIGS. 1A and 1B is conventionally known as a semiconductor device that includes a main circuit and a redundant circuit for protecting the main circuit. N-type diffusion layers 2a and 2b are formed on the surface of the P-type semiconductor conductor plate 10 to connect to a main circuit and a spare circuit corresponding to the main circuit, respectively.On the substrate 1, a diffusion layer 2a is formed.

An insulating shell 4 having openings 3a and 3b is coated on a portion corresponding to a part of 2b.

Furthermore, diffusion 1-2a, 2b is formed on a part of the tunic membrane 4.
An n-type polycrystalline silicon fuse 5 is formed which is connected to the openings 3a and 3b through the openings 3a and 3b. In a semiconductor device equipped with such a redundant circuit, when the main circuit is operating normally, the fuse 5 is connected to the diffusion layers 2a, 2.
b It is used in a K-connected state, but if a defect is confirmed, a laser beam is irradiated on the cut portion 6 of the fuse 50 (1), and the diffusion layers 2a and 2b are chemically cut off, thereby creating a redundant circuit. Activates to relieve defects in semiconductor devices.

(I&I points between the nails) However, in IIE's semiconductor devices, it is necessary to irradiate a large laser beam to prevent fusing, which may have an adverse thermal effect on surrounding elements. There is a drawback that the expanded tftli directly under the polycrystalline silicon fuse re-diffuses or causes crystal defects, deteriorating the characteristics of the semiconductor device.

(Invention Q) Purpose) This invention is an object that can eliminate the fusing of wiring layers at low cost! We offer one-night stays for semiconductor equipment that will be used for construction purposes.

(Invention σ) Summary) In order to achieve the above object, the present invention forms a recessed portion having an inclined surface on the surface of a semiconductor substrate, extends a wiring layer across the four portions, and adjusts the angle of the inclined surface to 111J. When the wiring layer is melted by the heating means, the wiring layer II is set so that it flows along the inclined surface of 14fJ and is fused.

Hereinafter, an example of the life i, 'itj of this invention will be explained based on 1.41j'j.

(Processing of the Invention) FIGS. 2 to 4 are cross-sectional views of elements according to each step, showing one manufacturing process of a semiconductor device 1 according to a partial example of the present invention.

First, one recess 12 is formed on the surface of the semiconductor substrate 11 by anisotropic etching, and then 14 diffusions +g 13 are formed on the surface of the substrate 11 to connect to the main circuit and the auxiliary circuit.

Next, an insulator 7515 is formed on the surface of the substrate 11. In addition, when forming the recess 12 in the semiconductor substrate 11, <1.1
), t)>Using the substrate 11& having a surface roughness, alkali etching or the like may be performed.

The depth of the base recess 12 is preferably approximately 4 μm. For example, the insulating layer 15 has a silicon oxide odor of about 1μQ).
Shape to thickness: □.

Next, the insulating film 15 is removed from the portions of the diffusion layers 13 and 14 by photolithography to form openings, and then the wiring layer (fuse) 16 is melted. to adhere to. Polycrystalline silicon is used as the material for such wiring layers, and the original material of the wiring layer is about 4000λ and -
It's masochistic to do that. If polycrystalline silicon is used as the wiring layer 16, phosphorous oxychloride (POCl) is used after deposition.
2) It is necessary to perform a heat treatment at 1000° C. for about 10 minutes in an atmosphere to diffuse phosphorus into the silicon to lower the resistance of the wiring layer 16.

A layer 16 subjected to such processing is then deposited by photolithography to form a layer 16.

It should be noted that molybdenum silicide (MoSi2) or aluminum (Al2) or the like can be similarly used for the polycrystalline silicon layer as the material film used for the urine layer 161C.

If molybdenum silicide, aluminum, etc. are used, heat treatment such as phosphorus diffusion is applied to form a pass layer of 16σ.
] There is no public security to lower the resistance.

When formed in this way, a groove 14 is formed on the surface of the semi-concave body plate, and the arrangement line 1-16 extends across the 12 recesses.
The construction is completed and the soil is built. In particular, on the concave portion 12, the layer 16 is on the IL page, and on the dou surface (7D).

When it is determined that a defect has occurred in the 1st column due to the 1st performance or performance test of the equipment in 1st shift of Φ half tit body with 1η structure, [For example, energy lJ is applied to a part of the soil on the surface f (1 layer 160),
When a 3μJ laser beam is emitted for 20Qns, the fourth
Shown in the figure. A part of the wiring layer I6 is melted at J, 5:'
The redundant circuit is activated by excitation ++lu by omitting it to the lower diagonal m and disconnecting it.

In addition, the angle of the inclined surface must be such that the wiring layer melts 7g when irradiated with the laser beam, and then 17) ↑'' is the unfolding angle. If the angle is too steep, the melted wiring layer 16 will not move to 0'II, and if the angle is too steep, it will cause a break in the layer.

Therefore, it is necessary to form a recess r as an underlying structure to provide the slope necessary for the movement of the fuse material in the Y1 section.

Further, the d-melting of the wiring layer is not limited to laser beam irradiation, but may be caused by Joule heat by irradiation with a laser beam or by immersing the wiring layer in the wiring layer 16.

(Invention σ) Effect) As described above in detail based on the actual bucket example, in the invention C, the liquid is melted by heating means. The 9-layer material flows q(
It is possible to melt the lower layer at a low ξ power with a σ] configured to cut the wiring by converting it into a .

Therefore, since the distance between the wiring layer and the element can be made shorter than that of the conventional semiconductor device, the small fR of the element can be increased.

[Brief explanation of the drawing]

FIG. 1 shows a conventional semiconductor device 1 (a sectional view and a plan view showing the structure of the semiconductor device, and FIGS. 2, 3, and 4 are shown in FIG. 4). FIG. 3 is a step-by-step device cross-sectional view showing the manufacturing process of ρ. 11... Semiconductor substrate, 12... Four parts, 13, 14
. . . Diffusion layer, 15 . . . Edge layer, 16 . . . T layer, 17 . . . Slanted surface.弗 1 fig. 3°) Fuhana 2 fig. 2 4- fig. 3 4- ichi fig. 4

Claims (1)

[Scope of Claims] (2) In a semiconductor device having a recess having an inclined surface formed on a surface of a semiconductor substrate, and a wiring layer extending across the recess, the wiring layer is heated to adjust the angle of the inclined surface. A semiconductor device characterized in that the wiring layer is configured to flow along the slope and break when melted by means. 2. The semiconductor device according to claim 1, wherein the a-layer is a polycrystalline silicon layer, a MOSi2 layer, or an AI layer. 3. The semiconductor device according to claim 1, wherein the heating means is performed by laser beam irradiation, electron beam irradiation, or energization of the wiring layer.