JPS6378551A - Wiring connection - Google Patents

Abstract

PURPOSE:To prevent disconnection at a stepped section and the increase of resistance, and to improve the reliability of connection by directly measuring the stepped section of the surface of a semiconductor device, varying the conditions of the irradiation of laser beams (irradiation power and a scanning rate) at the stepped section and enlarging the thickness of a deposited film in an additional wiring. CONSTITUTION:A semiconductor device 1 on an X-Y stage 10 is moved under a stepped measuring instrument 14, the position of an origin is detected, the X-Y stage 10 is shifted according to the position of coordinates at the position of correction, and an output value from the stepped measuring instrument 14 to the position of coordinates of a laser length measuring machine 18 is transmitted over a controller 20 through a data processor 19. Irregularities are measured, the X-Y stage 10 is transferred to a laser Chemical Vapor Deposition (CVD) processing section, the origin is positioned, a CVD gas is fed, irradiation power is increased or a scanning rate is decreased when the X-Y stage approaches to a stepped section with the data of the irregularities of the surface of the semiconductor device 1 from the data processor 19. Accordingly, a sufficiently thick film, step coverage, is improved even in an inclined section, thus preventing the increase of a resistance value and disconnection, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for connecting wiring of semiconductor devices such as ICs and LSIs by laser CVD.

[Conventional technology]

Modification of Semiconductor Devices In order to perform local inspections, design changes, etc., it is necessary to connect arbitrary wires within the semiconductor device. In recent years, laser CVD (Chemical Vap
or Dgposition) has begun to be applied to the above-mentioned wiring connections. For example, as shown in FIG. 2, an insulating film 5.
A wiring 4 such as AE + a protective film 5 such as S*01 are sequentially formed. When connecting the wirings 4α, dj by the laser CVD, holes 6α, 6b are formed in the protective film 5 by etching or the like to expose a part of the wirings 4α, 4b. After that, AA (CHs)j,
cd ((:1lj)t.

The semiconductor device 1 is placed in an atmosphere of material gases such as No (Co) 6 and v (co)a, and the laser beam 7 is irradiated from the holes 6α to 6b (from the wirings 4α to ah). As a result, the above material gas is decomposed and becomes AE, C
d, deposit a metal film 8 such as No and W (second
Figure (b)). When reaching the hole 6h, the irradiation of the laser beam 7 is stopped. Through the above steps, the wirings 4α and 46 are connected (FIG. 2 (C)).

In addition, as related to this type of method:

Extended Abstracts on the 17th
Conference on Lid State Devices and Materials.

Tokyo, 1985, pp. 196-196 (Es.
：tendadAbztructz of the
17th Confarmncg on 5oli
dState Davidcgz and AIat
griaLz, Tokyo, +985.

pp. 195-196).

[Problem that the invention seeks to solve]

However, the above-mentioned prior art only discusses forming a metal film by irradiating a substrate with a flat surface with a laser beam at a constant scanning speed. That is, as shown in FIG. 2, a typical semiconductor device has wiring, an insulating film, and a protective film formed thereon, and its surface has irregularities of several μm. For this reason, if the laser beam is scanned at a constant speed between two points where the wiring is to be connected, the film thickness T at the step part will be different from that at the flat part on the sputter-deposited film shown in Fig. 3 (α). The resistance value is small compared to the film thickness T, and the CVD film shown in FIG. 3(b) has a steep slope at the stepped portion, so there is a problem that wire breakage is likely to occur at the stepped portion.

An object of the present invention is to form a wiring film to be connected so as to prevent the above-mentioned disconnection or high resistance, and to improve the reliability of wiring connection.

[Means for solving problems]

The above purpose is to measure the unevenness on the surface of a semiconductor device in the scanning direction of the laser beam by a contact step measurement method prior to laser beam scanning, and when the laser beam approaches or reaches the step part of the unevenness, the laser irradiation control means This can be achieved by increasing the irradiation power of the laser beam or decreasing the scanning speed.

[Effect]

In the present invention, the unevenness measuring means is an electric micrometer or a contact type height difference measuring device, and the measurement results are sent to the laser irradiation control means. The laser irradiation control means makes the energy of the laser beam irradiated on the one step portion larger than that on the flat portion. That is, the irradiation power is increased or the scanning speed is decreased.

As a result, the thickness of the wiring metal film increases as shown in Fig. 4 (Fig. 4 shows the result of irradiating an Ar laser onto a Si substrate and depositing a No film from MoCC0)s.
Therefore, the resistance of the membrane increases at the step part.

This can prevent wire breakage.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows one embodiment of the apparatus used in the present invention.

A step measurement unit that measures and stores the unevenness on the surface of a semiconductor device along with its position, an optical system that irradiates the semiconductor device with laser light and observation light, and a laser irradiation control unit that controls the irradiation conditions of the laser light.

and a chamber section for performing laser CVD. The chamber section has an X-Y stage 10 on which a semiconductor device 1 is mounted, and a laser beam 7 and an observation beam 1.
2 is composed of a chamber 11 having an introduction window 13, a CVD gas supply device, and a vacuum evacuation device (not shown). 1
Reference numeral 4 denotes a measuring device for measuring the level difference of the semiconductor device 1, and the contact needle 15 measures the level difference on the order of several j. 16 is a reflecting mirror fixed on the X-Y stage 10, and the interferometer 1
7. The distance of movement of the X-Y stage 10 is measured by the laser length measuring device 18 . A data processing device 19 processes and stores data from the step measuring device 14 and the laser length measuring device 18.

A shutter 22.20 turns on and off the laser beam 7 from the laser source 21 according to data from the data processing device 19. Variable transmittance filter 23 that adjusts the amount of light. and a control device that controls the drive motor 24 of the XY stage 10.

25 is a lamp house of an observation optical system that coincides with the laser beam position and is used for positioning and observing the semiconductor device 1;
26 is an observation device.

In the above configuration, measurement of irregularities on the surface of the semiconductor device 1 will be described first. By moving the semiconductor device 1 placed on the X-Y stage 10 under the step measuring device 14 and driving the contact needle 15 on the surface as shown in FIG. 5 to detect the origin position pattern 9, Set the measuring distance of laser length measuring device 1B to O.
Clear to. By the way, when wiring is to be formed due to modification or design change of a semiconductor device, the coordinates of the modification location (6α16h18) shown in FIG. 2 are already known. , the XY stage 10 is moved according to this coordinate position. At this time, the contact needle 15 moves on the surface protection film 5 of the semiconductor device 10 as shown in FIG. 6)) is sent to the data processing device 19. In the data processing device, if the difference in level corresponding to the minute distance ΔX exceeds a predetermined value, ε,
Namely.

1h(x+Δx>-h<x>+>t The step value is stored. From this result, 1
Inclined portions X, -X, , X, -X4 of the surface protection film 5. and X, -X, etc., and send these data to the control device 2.
Send to 0.

Next, the formation of the wiring 8 will be explained based on the above data. The semiconductor device 1 after measuring the unevenness of the surface protection film 5 is
- The Y stage 10 is driven by the motor 24 to move to the laser CVD processing section. The origin position pattern of the contact needle 15 is determined by the observation device 26 using the observation light 12 from the lamp house 25, and the origin position is determined by using the pattern 9 in the same manner. x-
y-move the y-ji 10.

After that, CVD was supplied for 47 minutes. Irradiation of the laser beam 7 is performed by commands to open and close the shutter 22 from the control device 20, but the semiconductor device 1 table M from the data processing device 19 described above is
According to the unevenness data, the slope part X, -Xtx, -x
4. For x, -Xa, etc., the irradiation power is changed (at the inclined part, the irradiation power is increased from Pt to Pl.
)) or change the scanning speed (at the slope, reduce the scanning speed from 51 to S). Figure 5 (11)
The laser irradiation power at the inclined portion can be made larger than K. Note that, in practice, a predetermined distance δ is added before and after the inclined portion in consideration of margin for laser irradiation.

This results in a film that is sufficiently thick even on the slopes, ie.

Step coverage is improved, and problems such as increased resistance and disconnection are eliminated.

It should be noted that, although the description has been made in one axial direction, it goes without saying that similar results can be obtained in the orthogonal axial directions.

[Effects of the Invention] According to the present invention, when additional wiring is formed by laser CVD to connect the wiring in the semiconductor device, the step on the surface of the semiconductor device is directly measured and the laser beam irradiation conditions (irradiation) at one step are determined. By changing the power and scanning speed) and increasing the deposited film thickness of the additional wiring, it is possible to prevent wire breakage and high resistance at one step difference, and greatly improve the reliability of the connection.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is an explanatory diagram of a wiring connection method, Fig. 5 is an explanatory diagram of problems in the wiring connection method in the prior art, and Fig. 4 is a laser CVD FIG. 5 is a graph showing the relationship between laser irradiation conditions and wiring film thickness, and FIG. 5 is an explanatory diagram showing the wiring forming procedure of the present invention. 1... Semiconductor device, 4...
・・・・・・・・・Wiring 75・・・・・・・・・・・・
Protective film, 7...... Laser light. 8・・・・・・・・・－・・・Metal film. 10...---X-Y stage. 12・・・・・・・・Observation light 7 14・・・・・・・
...Step measuring device. +8... Laser length measuring device 19... Data processing device. 20... Control device, 21...
・Laser light source agent Patent attorney Ogawa ＃J′
Figure 1 12, Observation light 18 Laser pre-long story 21 Sea
The 4th picture of the trillion ball

Claims (1)

[Claims] 1. In a method of connecting wiring within a semiconductor device by adding wiring using the laser CVD method, the unevenness on the surface of the semiconductor device is measured using a step measuring device so as to correspond to the position of the unevenness on the surface of the semiconductor device, and the unevenness is A wiring connection method characterized in that the irradiation power of the laser beam is increased or the scanning speed is decreased at the step portion to increase the thickness of the wiring film for connection formed at the step portion.