JPS62259470A - Semiconductor device - Google Patents

Abstract

PURPOSE:To prevent a defect such as an electromigration or the like from occurring by providing aluminum alloy wirings which contain an element for forming a compound with a silicon as an additive, and interposing the nitride of a transition metal between the wirings and a silicon substrate. CONSTITUTION:An insulating film 11 is formed on an Si substrate 10 formed with a diffused layer 17, a hole is opened at electrode 15, sequentially covered with layers 16, 12-14, and the layers 14, 13, 12, 16 are successively etched. Here, the layers 12, 14 are Al2%-Si alloy layer, and TiN, ZrN of the layer 16 are formed by reactive sputtering method of Ti or Zr in mixture gas of N2 gas. Thus, it can effectively prevent a defect such as electromigration due to miniaturization of wirings, and also prevent the wirings from reacting with Si at the electrodes.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor device, and particularly to a semiconductor device having highly reliable and highly heat-resistant electrode wiring.

[Conventional technology]

In recent years, as the miniaturization of semiconductor devices has progressed, the wiring width of semiconductor devices has become significantly smaller, and as a result, many problems such as electromigration have started to occur.

In order to solve such problems, for example,
Many methods have been proposed, such as No. 31619.

However, with these conventional methods, it is difficult to effectively prevent the occurrence of electrode defects.

[Problem that the invention seeks to solve]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and provide a semiconductor device having fine electrode wiring that is less likely to be disconnected or short-circuited and has high reliability.

[Means for solving problems]

[In order to achieve the first objective, the present invention provides an AQ-based wiring layer in which electromigration is prevented by adding a metal capable of forming silicide in /Ml, and system wiring layer and 81 substrate or silicon (
Between the electrodes of i-id, etc.) Sj's from Thomas
A reaction between the electrode and the wiring is prevented by intervening a λ layer which prevents secondary rise, thereby preventing troubles that occur with the addition of metals.

[Effect]

Gold that forms the 18th grade silicide contained in AQ); A
In particular, the elements diffuse a lot through the grain boundaries in AQ, and
Q combines with Si added therein to form silicide, suppressing the diffusion and movement of AQ atoms through grain boundaries.

If the AQ wiring is in direct contact with the Si substrate during this silicide formation, Si will be sucked up from the substrate, but due to the thermally stable high point metal nitride layer such as TjN provided under the wiring, Si will be drawn up from the substrate. , which prevents Si from being sucked up from the substrate.

As is clear from FIG. 2, the sample without layer 6 cannot maintain its performance even after heat treatment at 400°C. One layer 16
Samples provided with this can withstand heat treatment up to at least 500°C, and in particular, when layer 16 is as thick as 200 nm, they can also withstand heat treatment up to 550°C. Therefore,
By providing the layer 16, the heat treatment temperature (
500° C.), it can be judged that there is sufficient reliability.

The thinner the layer 6 is, the better it is from the processing point of view, but the thinner the layer, the lower the heat resistance, so in reality, the film F is
It is desirable to determine [. Ti, N as the material of layer 16
, ZrN are shown in this example, but other transition metal nitrides such as ]4N and TaN are also thermodynamically stable and therefore have similar effects. Moreover, in order to make the electrical characteristics of the electrode portion desirable in practice, for example, silicide or the like may be provided between the layer 16 and Si.

[Embodiments of the invention]

The present invention will be explained below with reference to Examples.

Example 1 A sample having the structure shown in FIG. 1 was prepared and its heat resistance was examined. This sample is an S layer with a diffusion layer 17 (depth 0.3 μm)
j After forming the insulating film knob 11 on the substrate 10 and drilling an opening in the electrode part 15, the layers 16°1.2, 13.1 are formed.
The layers 14, 13 and 12, 16 were sequentially deposited using a sputtering method, and layers 14, 13 and 12, 16 were sequentially etched using a normal photo-etching process. Layer】2. and ]4 are both A 0.2% Sj alloy layers (each 500 nm thick). λ・116 is of two types: TiN and ZrN, 1 layer 13 is T
a.

Five types of samples as shown in Table 1 were prepared by combining two types of Tj. Sample #3 was not provided with M416. Layer] 6 TiN.

ZrN was formed by reactive sputtering of Ti or Zr in a mixed gas of Ar gas and N2 gas. The sample prepared as described above is heat treated in a hydrogen atmosphere, and the reverse breakdown voltage of the diode formed on the diffusion layer 17 is approximately 5.
The defective rate was calculated for 0 samples. The heat treatment was performed at 50°C intervals starting from 400°C, and the sample was heated once at each temperature.
Holds time. Figure 2 shows the results.

Table 1 Example 2 Using #1, #2 and #3 wiring parts (length 1 field 1 width 1.3 μm) manufactured through the same process as Example 1, current conduction test (250°C, current density 1×106 A/cd). Table 2 shows the wiring structure of each sample and the average lifespan (time until half of the 20 wirings, or 10 wirings, break). Compared to the conventional wiring #3, the wiring with the structure #1 and #2 has a lifespan several ten times longer than that of the conventional wiring #3, whereas the average lifespan of sample #3, which does not have the nitride layer 16, is much longer. was confirmed to be short.

Table 2 [Effects of the Invention] As described above, according to the present invention, problems such as electromigration caused by miniaturization of wiring can be effectively prevented, and reactions between the wiring and Si at the electrode portion can also be prevented. This is extremely useful as a semiconductor device with a high degree of integration.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a curve diagram showing the effects of the present invention. 10... Si substrate, 11... Insulating film layer, 12...
AQ. Si layer, 13-High melting point metal layer such as Ta, Ti, 14...
AQ, Si layer, 15...electrode portion, 16...TjN. Nitride layer such as ZrN, 17...diffusion layer.

Claims (1)

[Claims] 1. A semiconductor device comprising an aluminum alloy wiring containing as an additive element an element that forms a compound with silicon, and at least a layer of transition metal nitride is interposed between the wiring and the silicon substrate. .