JPH0691087B2 - Method for manufacturing semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] In a method for manufacturing a semiconductor device according to the present invention, when a via hole (a generic term for a contact hole and a through hole) is buried by melting an aluminum (Al) deposited film by pulse laser light irradiation, Si Irradiation with pulse width of 100 ns or less is set in order to eliminate the inconvenience of junction breakage due to Al / Si reaction induced at the contact with the substrate and thermal destruction of the lower Al wiring in the multilayer Al wiring structure. By doing so, the via hole can be filled without causing the excessive Al / Si reaction and the destruction of the lower layer Al wiring as described above.

[Industrial application field]

The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device in which a via hole is buried by melting an Al deposited film by pulse laser light irradiation.

[Background of technology]

FIG. 3 is a sectional view showing a state in which Al is deposited in the via hole. Reference numeral 1 is a Si substrate, 2 is an interlayer insulating film, and 2a is a via hole. When depositing Al3 in the via hole 2a, if a method such as sputtering or vapor deposition is used, particularly in a via hole having a high aspect ratio (depth / diameter), the adhesion rate to the sidewall of the via hole is poor, as shown in FIG. Poor connection with the Si substrate 1 is likely to occur. Similarly, in the multilayer Al wiring structure, a connection failure between the upper layer Al wiring and the lower layer Al wiring is likely to occur.

In order to prevent such connection failure, a method of irradiating a pulsed laser beam from above Al3 to melt Al3 and fill the via hole 2a is conceivable. However, if the heating time is set to a relatively long time, for example, on the order of μs, depending on the irradiation of this pulsed laser light,
There is a disadvantage that an excessive Al / Si reaction is induced in the contact portion with the Si substrate 1 or the lower Al wiring is thermally destroyed in the multilayer Al wiring structure.

[Means for Invention]

As shown in FIG. 1, the semiconductor device manufacturing method according to the present invention uses aluminum 3 or an aluminum compound with a pulse width of 10
The via hole 2a is filled by melting with the pulsed laser light 4 of 0 ns or less.

[Action]

Since the pulse width is relatively short (100 ns or less), it induces excessive Al / Si reaction that causes junction breakdown, and lower layer A
l Does not cause thermal damage to the wiring.

〔Example〕

FIG. 1 is a sectional view showing an embodiment of a method of manufacturing a semiconductor device according to the present invention. In FIG. 1, the same components as those in FIG. 3 are designated by the same reference numerals and the description thereof will be omitted. Fig. 1 (A)
As shown in, pulsed laser light 4 emitted from above Al3
Is, for example, an ArF (wavelength λ = 193 nm) excimer laser,
Set the bassle width to a relatively short order of 100ns or less. The irradiation of the pulsed laser beam 4 melts Al3, and as shown in FIG. 1 (B), the via hole 2a is uniformly buried to form an Al layer 3a.

As shown in the pulse width vs. depth characteristic diagram of the Si reaction layer in FIG. 2, the pulsed laser light 4 causes the Si layer to react only up to a depth of 0.3 μm as long as a pulse width of 100 ns or less is applied. Therefore, the excessive Al / Si reaction that shows the junction breakdown is not induced in the contact portion with the Si substrate 1. Further, since the irradiation time is short, the lower Al wiring will not be thermally destroyed even when applied to the multi-layer Al wiring structure.

As shown in FIG. 2, the longer the pulse width, the greater the depth of the Si reaction layer. A Si reaction layer having a pulse width of 100 ns and a depth of about 0.33 μm is formed. The depth of the 0.33 μm layer corresponds to the depth of the source and drain of LSIs made up of currently commercialized MOSFETs, and the pulse width of 100 ns is the allowable limit. Since the depth of the source and drain will become shallower as the integration of LSI becomes higher, it becomes necessary to use pulsed laser light with a short pulse width.

The substance to be buried in the via hole 2a may be pure Al or a compound of Al and another substance.

〔The invention's effect〕

According to the present invention, since aluminum or a composite of aluminum and another substance is melted with a pulsed laser light having a pulse width of 100 ns or less and embedded in a via hole, the laser light irradiation time is relatively short, As a result, an excessive Al / Si reaction is not induced in the contact area with the Si substrate, and even when applied to a multilayer Al wiring structure, it does not cause thermal damage to the lower layer Al wiring. It is possible to obtain high-quality semiconductor devices.
It has features such as being able to sufficiently cope with the present situation where the depth of the drain becomes shallow.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the method of the present invention, FIG. 2 is a characteristic diagram of pulse width of pulsed laser light versus Si reaction layer depth, and FIG. 3 is a sectional view showing a state in which Al is deposited in a via hole. It is a figure. In the figure, 1 is a Si substrate, 2 is an interlayer insulating film, 2a is a via hole, 3 is Al, 3a is an Al layer after melting, and 4 is a pulsed laser beam.

Claims (1)

[Claims] 1. A semiconductor characterized in that aluminum (3) or a compound of aluminum and another substance is melted by a pulse laser beam (4) having a pulse width of 100 ns or less and embedded in a via hole (2a). Device manufacturing method.