JPH0497530A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To make step coverage of Al better and prevent disconnection of Al in a contact hole portion where the aspect ratio is high because melted Al directly flows into the contact hole by applying melted Al onto a semiconductor substrate. CONSTITUTION:After a diffusion layer 2 is formed on an Si substrate 1, an S1O2 film 3 is formed on the substrate 1. Next, the S1O2 film 3 is dry etched with, for example, resist as a mask, in order to form a contact hole 4. While the substrate 1 is kept heated to an appropriate temperature below 500 deg.C, a melted Al film 6 is applied onto the surface of the substrate 1 by dropping melted Al of approximately 700 deg.C through a nozzle 11 onto the rotating Si substrate 1. At this time, even if the surface of the film 6 is not flat, it can be made flat by etching. The coverage of Al, in particular, in the step-difference portion, is improved considerably. The disconnection of Al can be prevented, improving the reliability of devices.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing a semiconductor integrated circuit device.a.Prior Art An Al film is used as a metal wiring material on a semiconductor substrate. Although sputter deposition has become the mainstream method for forming films, Figure 4 is a cross-sectional view of a semiconductor device manufactured by this conventional sputter deposition method.
Mold with diffusion layer 2 formed on Si substrate 1 S mold formed on Si substrate 1
A contact hole 4 is formed by forming a film 3 on 10 and dry etching it using, for example, a resist as a mask.Also, an Al film 6 is formed by sputter deposition.
In the conventional method configured in this way, even though the small step coverage of A1 at the step part shown in the figure is a big problem, it is difficult to obtain &Al-
Aj alloy IL MO, W such as 8j-Cu, Al-8i
, a high melting point metal film such as Ta, and M o Si *
To form silicide films such as WSig, the following high-speed sputtering method is used to alleviate the above problems. It is possible to form a metal film with strong adhesion strength without heating the substrate, and because the film is formed in a low vacuum of about 10-” Torr to 10-” Torr, the “wrapping” of the deposited metal is improved. However, the problems that the present invention aims to solve have been resolved by the present invention, which is characterized by good step coverage of the wafer step part and higher sputtering efficiency than normal sputtering methods. As the aspect ratio increases ((Even in conventional manufacturing methods such as high-speed sputtering, the step coverage of A1 in the contact hole portion becomes worse, and when creating devices with finer structures, Al
In view of this problem, the present invention has been designed to solve the problem of wire breakage, etc.
The purpose of the present invention is to provide a manufacturing method that does not cause disconnection of A1 wiring by coating JQ. The formed insulating film is selectively removed to form a contact hole, and molten Al is applied to the semiconductor surface to fill the contact hole portion.The action of the present invention is as follows. Since the molten Al flows directly into the contact hole, the step coverage of k Al is improved in the contact hole portion with a large aspect ratio, and disconnection of Al can be prevented. will be explained with reference to FIGS. 1 to 4 (Embodiment 1) FIGS. 1A to 1C are manufacturing process cross-sectional views showing the first embodiment of the present invention. First, a diffusion layer 2 is formed on a Si substrate 1.S+0*II! 3 is formed, but the next
The contact hole 4 is formed by dry etching the a film 3, and then, as shown in FIG.
By dropping A15 molten to about 700°C from the nozzle 11 onto the rotated Si substrate 1 while heating it to an appropriate temperature below 0°C, the molten Al is deposited on the surface of the 81 substrate 1.
! :Apply 6. Even if unevenness occurs on AlH3, it can be made flat by etching.
Figure 4 is a cross-sectional view of the contact hole portion created by the above process, and shows that the coverage of A1, especially at the stepped portion, has been greatly improved compared to the conventional example shown in Figure 4. Improving the reliability of (Example 2)
) FIGS. 2A to 2C are cross-sectional views showing the manufacturing process of a second embodiment of the present invention. In FIG. 2A, first, a diffusion layer 2 is formed on an 81 substrate 1. The O* film 3 is formed, and the 5101 film 3 is dry-etched using, for example, a resist as a mask to form a contact hole 4. Next, S
A metal film 7 of a desired thickness having a melting point higher than A1 is formed on the entire surface of the i-substrate 1, but then, for example, t'L S
While heating the i-board 1 to an appropriate temperature of 500°C or less, 7
By dropping Al5 melted at about 00°C onto the rotated Si substrate 1 from the nozzle 11, the A1 film 6 is applied to the surface of the Si substrate 1. At this time, even if the Al film 6 has unevenness, it is flattened by etching. can be 4th number mi
For example, according to this embodiment, a wiring pattern is formed by dry etching AlIO2 using a resist as a mask.
The high melting point metal film 7 and the Al film 6 adhere more easily than the lIO2 adhesion, and as shown in FIG. In the above process, before forming the high melting point metal film 7, the silicide M8 of the desired thickness is
The high melting point metal film 7 and Si may be formed during heat treatment.
Direct reaction with the substrate 1 is suppressed by this silicide film 8, resulting in a low contact resistance value.Also, the silicide film 8 and the high melting point metal film 7 are formed using a vapor deposition method such as a high-speed sputtering method. (Example 3) Figure 3C-C is a cross-sectional view of the manufacturing process showing the third example of the present invention.In Figure 3A, first, a diffusion layer 2 was formed on a Si substrate 1. A 5102 film 3 is formed on a resistive Sl substrate 1, and a contact hole 4 is formed by dry etching the 5102 film 3 using, for example, a resist as a mask.

Furthermore, a metal film 7 having a melting point higher than that of A1 is formed as a lower layer wiring film on top of the metal film 7. Sputter deposition may be used to form the high melting point metal film 7. A high melting point metal 7 is used as a lower wiring film, and an interlayer insulating film 9 of about 800 nm is formed thereon, and this is dry etched using, for example, a resist as a mask to form a contact hole to expose the lower wiring film. Next, a metal film 7 having a melting point higher than that of Al is again formed on the interlayer insulating film 9, and a wiring pattern is formed by dry etching this using, for example, a resist as a mask. By applying the molten Al film 6, which will become the upper layer wiring film, by dropping A15 melted to about 700°C onto the rotated Si substrate 1 from the nozzle 11 while heating it to an appropriate temperature. Although the contact hole portion of the insulating film 9 is filled with Al, FIG. 3 is a cross-sectional view in which the Al film 6 as an upper wiring film is selectively removed in the contact hole portion of the interlayer insulating film 9. As described above, according to this embodiment, the contact hole with a high aspect ratio
According to the present invention, it is possible to form a connection part of multilayer wiring with good coverage, which leads to an improvement in the reliability of the device.Effects of the Invention As is clear from the above embodiments, according to the present invention, molten A1 is directly filled into contact holes. let's eat
With the future miniaturization of contact holes, 1. X. Compared to conventional film formation methods such as high-speed sputtering, the step coverage of Al in the contact hole area is better, and A.
This prevents disconnection of the l and reduces contact resistance, which improves device reliability.

[Brief explanation of the drawing]

1st doctor 2nd @ Fig. 3 shows the first, second, and third embodiments of the present invention, respectively.
Fig. 4 is a half-fold cross-sectional view of a semiconductor device showing a conventional embodiment. Mut...81 substrate, 2...Diffusion #3...S+02
Trap 4... Contact hole L/, 5... Molten Al, 6... Al trap 7... High melting point metal film 8.
...Silicide WL 9...Interlayer insulation [10...Heating device rL 11...Nozuno - Name of agent Patent attorney
Shigetaka Awano

Claims (3)

[Claims] (1) After forming an insulating film on one main surface of the semiconductor substrate,
A semiconductor comprising the steps of selectively removing the insulating film to form a contact hole, and applying molten Al to the surface of the semiconductor substrate, electrically connecting the Al and the semiconductor substrate. Method of manufacturing the device. (2) After forming the contact hole, a metal film of a desired thickness having a melting point higher than Al is formed on the surface of the semiconductor substrate, and then molten Al is applied. A method for manufacturing a semiconductor device. (3) After forming an insulating film on one main surface of the semiconductor substrate,
selectively removing the insulating film to form a contact hole; forming a lower metal wiring film having a melting point higher than Al on the surface of the semiconductor substrate; and forming an interlayer insulating film on the lower metal wiring film. forming and selectively removing it to form a contact hole, and applying molten Al that will become an upper layer wiring film on the semiconductor substrate, and connecting the lower layer metal wiring film and the upper layer wiring through the contact hole. A method for manufacturing a semiconductor device, the method comprising electrically connecting a semiconductor device to a film.