JPH0226051A - Manufacture of semiconductor device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method of manufacturing wiring for a semiconductor device.

[Conventional technology]

The conventional method for manufacturing semiconductor devices is disclosed in Japanese Patent Application Laid-Open No. 14273/1986.
9, after forming a high melting point metal layer on the insulating film and the surface of the contact opening, heat treatment was performed to make the metal surface a metal nitride, and then a wiring metal was formed on the metal nitride.

[Problem to be solved by the invention]

In recent years, as semiconductor devices have become smaller, contact openings have also become smaller. Accordingly, a bias sputtering method has been used to improve the coverage of the wiring metal in the contact opening, but in this method, the temperature of the substrate increases due to the application of a bias to the substrate. This causes the wiring metal (eg, A'') to penetrate the underlying junction, increasing leakage current.

In addition, in recent years, the wiring of semiconductor devices has become more multilayered.
The leakage current increases in the same way as described above due to the heat generated when forming the glabellar insulating film between the wirings and the upper layer wiring.

The above-mentioned conventional technology has a problem in that the effect of preventing the wiring metal from penetrating the bond due to the heat of the process described above is weak. That is, the metal in the wiring diffuses into the metal nitride due to the heat of the subsequent process, penetrates the junction, and increases leakage current.

The present invention has been developed to solve these problems, and its purpose is to achieve mass productivity and reliability by preventing wiring metal from diffusing even when heat is applied in post-processing, and preventing junction leakage current from increasing. The purpose of the present invention is to provide a method for manufacturing an electrode with high properties.

[Means to solve the problem]

The method for manufacturing a semiconductor device of the present invention includes forming a high melting point metal layer on the insulating film and the surface of the contact opening, heat-treating the layer, and then ion-implanting silicon or oxygen into the high melting point metal layer. , a conductive wiring is formed on the high melting point metal layer.

〔Example〕

FIGS. 1(a) to 1(c) are manufacturing process diagrams in an embodiment of the present invention. The present invention will be explained below with reference to FIG.

First, a diffusion layer 108 is formed on the surface of a silicon substrate 103.In this embodiment, 103 is a P-type silicon substrate, and 108 is an N-swelled diffusion layer.Next, an insulating film 102 is formed, and a contact opening is formed. After the formation, a high melting point metal layer 101 is formed on the insulating film and the surface of the contact opening.In this example, titanium was sputtered as the high melting point metal. (FIG. 1(a)) Next, heat treatment is performed.Although the heat treatment can be performed in a normal horizontal oxidation furnace, in this example, a lamp annealing furnace was used as the high-speed heat treatment furnace. As a result, titanium nitride 105 is formed on the surface of the titanium on the N-type diffusion layer in the contact opening, and titanium silicide 106 is formed at the interface with the substrate. Further, silicon or oxygen 104 is ion-implanted into the titanium nitride surface. The dose at this time is 10'4~10''c
s-', an acceleration voltage of 20 to 40 KeV was used. As a result, the silicon or oxygen concentration in titanium nitride 105 is 1
Q l 8 to 1020 am-3. (Figure 1(b)
)) Thereafter, a conductive wiring 107 was formed on the ion-implanted titanium nitride 105 by sputtering. (FIG. 1(C)) In the above embodiment of the present invention, sputtered titanium 1
01 becomes titanium nitride 105 by heat treatment in a lamp annealing furnace. In the conventional technology, this titanium nitride forms a columnar crystal, and the metal in the wiring is diffused along the dale line by heat in a subsequent process, leading to junction leakage.In the present invention, silicon or oxygen is ion-implanted into the titanium nitride. Introduced by This silicon or oxygen exists in the drain of titanium nitride, and in this embodiment, plays the role of preventing diffusion of A1.

FIG. 2 is a diagram showing that leakage current is reduced by the present invention. It shows the leakage current distribution of the junction after the Aj wiring was formed and heat treated at 450° C. for 3 hours.

The sample has 10,000 contact holes.
It is a P-junction, and the vertical axis of the graph represents the frequency, and the horizontal axis represents the logarithm of the leakage current. The junction leakage current distribution of the contact according to the prior art shows that 10% to 20% leakage occurs (Fig. 2(a)), but no leakage occurs in the contact according to the present invention (Fig. 2(b)). )) In the above embodiment, Aj was used as the conductive wiring, but the same effect can be obtained even if high melting point metal wiring such as tungsten is used. Further, in the above embodiment, it was shown that the present invention is effective for the N''/P- diffusion layer, but the same effect can be obtained for the P''/N- diffusion layer.

Further, according to the present invention, when a sputtering method is used to form the conductive wiring, the wettability between the conductive wiring and the high melting point metal wiring is improved, and the step coverage of the contact opening is also improved.

As a result, electromigration defects in this portion are less likely to occur, improving the reliability of the semiconductor device.

〔Effect of the invention〕

As described above, according to the present invention, a high melting point metal layer is formed on the insulating film and the surface of the contact opening, and then heat treated, and then silicon or oxygen ions are implanted into the high melting point metal layer. This has the effect of preventing wiring metal from diffusing during a thermal process after wiring formation, preventing junction leakage, and providing stable contact. Also,
It also has the effect of improving wettability with the upper layer wiring metal, improving step coverage, and improving electromigration characteristics as a result.

[Brief explanation of the drawing]

FIGS. 1(a) to 1(c) are manufacturing process diagrams showing one embodiment of the present invention. FIGS. 2(a) and 2(b) are graphs of junction leakage current distributions showing the effects of the present invention, with FIG. 2(a) being the conventional technique and FIG. 2(b) being the graph according to the present invention.・Titanium・Insulating film・P-type silicon substrate・Silicon or oxygen・Titanium nitride・Titanium silicide・Aj ・N expansion diffusion layer and above Applicant: Seiko Epson Corporation Representative Patent attorney Masatoshi Kamiyanagi (1 other person) Rin 10 ( c.
)

Claims (1)

[Claims] After forming a high melting point metal layer on the insulating film and the surface of the contact opening, heat treatment is performed, and then silicon or oxygen ions are implanted into the high melting point metal layer, and then conductive wiring is formed on the high melting point metal layer. 1. A method of manufacturing a semiconductor device, comprising: forming a semiconductor device.