JPH03225829A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To fill a cavity sealed by an alloy wiring layer with the layer and to improve economy and reliability by forming the layer on a semiconductor substrate and then heating it in a high pressure inert gas atmosphere. CONSTITUTION:An alloy wiring layer 2 is formed on a semiconductor substrate 1 having a step 1a, and the substrate 1 is heat treated in a high pressure gas atmosphere. The substrate 1 in which such an Al wiring layer 2 is formed is placed in a holder 5, conveyed into the processing chamber 4 of a processor, the chamber 4 is sealed, and argon gas is supplied from an argon gas cylinder 8 to the chamber 4 through a pressure regulator 9. A current is supplied to a heater 6 by using a temperature regulator 7 in this state to heat it, thereby heating the substrate 1. Thus, the layer 2 having an excellent step coverage can be formed to be completely filled in the contact hole 1a of the substrate 1.

Description

[Detailed Description of the Invention] [Summary] Regarding the improvement of the method of forming an alloy wiring layer on a semiconductor substrate having steps, the present invention relates to a step coverage method in which the contact hole of the semiconductor substrate is completely filled with the alloy wiring layer. The purpose of the present invention is to provide a method for manufacturing a semiconductor device that makes it possible to form a good alloy wiring layer. The method is configured to include a step of processing.

[Industrial application field]

The present invention relates to a method for manufacturing a semiconductor device, and particularly to an improvement in a method for forming an alloy wiring layer on a semiconductor substrate having steps.

In recent years, the wiring layers of semiconductor devices have been formed as thin films by sputtering using aluminum or aluminum alloy as a material. However, as elements become smaller and wiring structures become more multilayered, the aspect ratio of the steps of the underlying substrate, That is, the aspect ratio is increasing, making it difficult to form a wiring layer with good step coverage (hereinafter referred to as step coverage).

Under the above circumstances, there is a need for a method of manufacturing a semiconductor device that can form a wiring layer with good step coverage.

[Conventional technology]

A conventional method for manufacturing an M alloy wiring layer of a semiconductor device will be explained in detail with reference to FIG.

In the conventional semiconductor device manufacturing method, as shown in FIG. 4, a semiconductor substrate 2 with a contact hole 21a formed therein is
An M alloy wiring layer 22 is formed on the surface of the substrate 1 by sputtering.

In this case, if the aspect ratio of the contact hole 21a is large, the contact hole 21a is
The M alloy wiring layer 22 is formed on the wall surface of the wall, and a void as shown in the figure is generated inside, making it impossible to fill the M alloy wiring layer 22, thereby forming a wiring layer with good step coverage. is difficult.

For this reason, the temperature of the semiconductor substrate 21 during film formation is set to a high temperature near the melting point of the material of the wiring layer to improve the coverage and flatness.

However, since it is difficult to accurately know the temperature of the semiconductor substrate 21 during the Yuvatuta process, the process is currently performed based on the correlation between the set temperature of the stage on which the semiconductor substrate 21 is placed and the results of the Subafuta film formation. However, since the state of heat transfer varies depending on the state of contact between the stage and the semiconductor substrate 21, it is difficult to obtain good reproducibility.

[Problem to be solved by the invention]

In the conventional semiconductor device manufacturing method described above,
When the aspect ratio of a contact hole in a semiconductor substrate becomes large, it becomes difficult to stably fill the contact hole with an alloy wiring layer, and it becomes difficult to form a wiring layer with good step coverage. there were.

In view of the above-mentioned circumstances, the present invention provides a method for manufacturing a semiconductor device that makes it possible to form an alloy wiring layer with good step coverage in which the contact hole of a semiconductor substrate is completely filled with the alloy wiring layer. It is intended for the purpose of providing.

[Means to solve the problem]

A method for manufacturing a semiconductor device according to the present invention is configured to include the steps of forming an alloy wiring layer on a semiconductor substrate having a step, and heat-treating the semiconductor substrate in a high-pressure gas atmosphere.

[Effect]

That is, in the present invention, an alloy wiring layer is formed on a semiconductor substrate having steps, and this semiconductor substrate is heat-treated in a high-pressure gas atmosphere, so that the alloy wiring layer is softened by the heat treatment and is softened by the pressure of the high-pressure gas. Since the alloy wiring layer is press-fitted into the step of the semiconductor substrate, the space created in the alloy wiring layer within the step is eliminated, making it possible to form an alloy wiring layer with good step coverage.

〔Example〕

Hereinafter, one embodiment according to the present invention will be explained in detail with reference to FIG. 1, and another embodiment according to the present invention will be explained in detail in the order of steps with reference to FIG. 2.

In one embodiment of the present invention shown in FIG. 1, first, as shown in FIG. Form.

The composition of this M alloy wiring layer 2 is aluminum containing 1% silicon.

Since the diameter of this contact hole 1a is 0.5 μm, the depth is 1 μm, and the aspect ratio is large, a void 2a sealed by the M alloy wiring layer 2 is formed inside this contact hole 1a, as shown in the figure. It is formed.

The semiconductor substrate 1 with such an M alloy wiring layer 2 formed thereon was mounted on the holder 5, and carried into the processing chamber 4 of the processing apparatus used in the present invention as shown in FIG. 3, and the processing chamber 4 was sealed. Thereafter, 500 kgf/cd of argon gas is supplied from an argon gas cylinder 8 to the processing chamber 4 via a pressure regulator 9.

In this state, current is applied to the heater 6 using the temperature controller 7 to raise the temperature, and the semiconductor substrate 1 is heated to 550°C.

When such heating and pressure treatment is performed for about 20 minutes, the contact hole l of the semiconductor substrate 1 is formed as shown in FIG.
The inside a is completely filled with the M alloy wiring layer 2, and it becomes possible to form the M alloy wiring layer 2 having good step coverage on the surface of the semiconductor substrate 1.

In another embodiment of the present invention shown in FIG.
As shown in FIG.
is mounted on the holder 5 and carried into the processing apparatus shown in FIG.

Then, the temperature of the semiconductor substrate 11 is maintained at 450° C. and heated for 10 minutes to bring the semiconductor substrate 11 and the M film 3 into close contact as shown in FIG. When the temperature of the semiconductor substrate 11 is increased to 550° C., the portion of the At film 3 that was in contact with the semiconductor substrate 11 is press-fitted into the contact hole lla of the semiconductor substrate 11, as shown in FIG. 2 (C1).
It becomes possible to form a wiring layer with good step-knob coverage on the surface of the semiconductor substrate 11.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, after forming an alloy wiring layer on the surface of a semiconductor substrate, it is heated in a high-pressure inert gas atmosphere, so that the vacancies sealed by the alloy wiring layer are removed. It has the advantage of being able to be filled with an alloy wiring layer, and it is possible to provide a method for manufacturing a semiconductor device that can be expected to be significantly economical and to improve reliability.

[Brief explanation of drawings]

Fig. 1 is a side sectional view showing an embodiment according to the present invention in the order of steps; Fig. 2 is a side sectional view showing another embodiment according to the invention in the order of steps; Fig. 3 is a schematic structure of a processing apparatus used in the present invention. FIG. 4 is a side sectional view showing a conventional method of manufacturing a semiconductor device.
It is. In the figure, Lll is the semiconductor substrate, la and lla are contact holes, 2 is M alloy wiring layer, 2a is hole, 3 is A/film, 4 is processing chamber, 5 is holder, 6 is heater, 7 is temperature control 8 is a cylinder, and 9 is a pressure regulator. :/ (Al Formation of M alloy wiring layer (2) by sputtering method~) State after pressure/heat treatment Side cross-sectional view showing an example according to the present invention in the order of steps Figure +a+ AZ film (3) Toilet surface diagram showing another embodiment of the present invention in the order of steps; Schematic structural diagram of the processing equipment used in the present invention; Diagram showing the conventional manufacturing method of a semiconductor device. Side sectional view diagram

Claims (1)

[Claims] The method is characterized by comprising the steps of: forming an alloy wiring layer on a semiconductor substrate (1) having steps; and heat-treating the semiconductor substrate (1) in a high-pressure gas atmosphere. A method for manufacturing a semiconductor device.