JPS59148350A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a conductive film of high reliability with good efficiency by adhering an aluminum film on a substrate, adhering a titanium nitride thin film, and changing said films into a wiring layer by patterning. CONSTITUTION:The first aluminum film 12 is adhered on the semiconductor substrate 11, and further the titanium nitride thin film 13 is formed. The thin film 13 and the aluminum film 12 are selectively dry-etched and thus patterned, resulting in the formation of the wiring layer. After forming an insulation film 14 on this wiring layer, a desired connection window 15 is selectively etched, and said films 14 and 13 are removed. An aluminum wiring layer 16 is adhered over the entire surface by a sputtering method, and a resist film 17 is applied.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and particularly to an improvement in a method for forming a conductive wiring layer formed on the surface of a semiconductor integrated circuit element.

(b) Prior Art and Problems In a semiconductor integrated circuit (process 0), a large number of active elements and passive elements are provided on a semiconductor substrate, and these elements are connected to each other through conductive wiring layers. An aluminum film is often used as the conductive wiring layer, and the aluminum film is formed into a multilayer structure with an interlayer insulating film interposed therebetween for high integration.

In the conventional method, an aluminum wiring layer with such a multilayer structure is formed by depositing an aluminum wiring layer on the entire surface of the semiconductor substrate 1 by the usual 7-butter method or the like as shown in FIG. A 17-μm aluminum (Al) wiring pattern 2 is formed by selectively etching using the dry etching method of Silicate glass film (
A PSG film) 3 is formed. However, in this case PSG
When growing the film 3, the first A [wiring pattern is about 42
Because of the high temperature treatment at 5° C., the aluminum crystals are rearranged in the vertical direction, resulting in the formation of protrusions 4 on the AI wiring pattern 2, as shown in the figure. Therefore, as shown in FIG. 2, after connecting windows 5 are selectively opened in predetermined positions of the insulating film 8 by plasma etching, the second kl wiring layer 6 is deposited and the 21st ffi wiring layer is patterned.
II when applying the resist film 7 and performing mask alignment.
The resist film 7 at point A on I-note 4.

It was damaged due to contact between the glass mask and the protrusions, and a part of the second AA wiring layer 6 (point A) was sometimes disconnected as shown in FIG. Various methods have been proposed to prevent such protrusions 4 from forming on the first Ad wiring pattern 2. For example, after forming the first i wiring pattern, an aluminum oxide film is formed on the surface thereof by anodizing. is proposed as one of them. However, the positive oxidation method l-1, Ga! , 17-), and if the aluminum oxide film is thin, there is a risk of producing large protrusions in the post process. If contact with the wiring layer 6 cannot be made and a post-process is added to remove the aluminum oxide in the connection window 5 by etching with dilute hydrofluoric acid, the cross-sectional shape of the connection window 5 becomes an inverted i-par type, and the second AI
If the wiring layer 6 had insufficient capacity, there was a possibility that the wiring layer 6 would be disconnected. Other methods also have similar problems in terms of reliability.

((3) Purpose of the Invention The purpose of the present invention was made in view of the above problems, and it is possible to efficiently and highly reliable conductive material by eliminating the need for an anodic oxidation process and preventing protrusions from forming on the aluminum film. An object of the present invention is to provide a method for manufacturing a semiconductor device in which a film can be formed.

■Structure of the Invention In order to achieve the object, the method for manufacturing a semiconductor device of the present invention consists of depositing an aluminum film on a substrate.

It is characterized in that it further includes a step of forming a patterned wiring layer from the quantized titanium thin film and the aluminum film after depositing the titanium nitride thin film.

(e) Examples of the invention Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 to FIG. 7 are cross-sectional views of important parts of the process for explaining one embodiment of the present invention. In FIG. 4, the semiconductor substrate 11
A first aluminum film 12 with a thickness of about 1 μm is deposited thereon by ordinary sputtering, and titanium nitride (TtN
) Thin film 18 is sputtered to a thickness of about 1000″A,
It is deposited on the aluminum film 12. In this case, it is preferable to form them in the same chamber. Next, as shown in FIG. 6, a salt-purple reactive gas such as carbon tetrachloride (CC14), boron trichloride (BO6B), or a mixture of the two gases is used using a resist (not shown) as a mask. Then, the titanium nitride thin film 18 and the aluminum film 12 are selectively etched and patterned to form a wiring layer, and then the resist film is removed. In this case, since the etching rates for the reactive gas of the titanium diluted thin film B and the aluminum film 12 are selected to be approximately the same, it is possible to form a good pattern. After forming an insulating film 14 made of phosphorous liquid gas (PSG), a desired connection window 15 is formed in the insulating film 14 using carbon tetrafluoride (O2).
The insulating film 14 and the titanium nitride thin film 13 within the connection window 15 are selectively etched using a resist film (not shown) as a mask using a mixed gas of F4) and oxygen (0).In this case, the aluminum film I2 is exposed to a high temperature of approximately 425°C during PSG growth, but the aluminum surface is covered with a titanium nitride thin film 18 that does not oxidize either aluminum (AJ?) or silicon (Sx).
Protrusions due to rearrangement of A4 atoms as described above do not occur. Next, the resist film is removed, and as shown in FIG. 7, a line layer 16 is deposited on the entire surface of the second aluminum wiring layer by sputtering, and a resist film 17 is applied on the aluminum wiring layer for mask alignment. Since there is no protrusion mentioned above, patterning can be performed without damaging the resist film 17. Therefore, using the patterning resist film 17 as a mask, the second aluminum wiring layer 16 is patterned without disconnection.

(g) As described in detail, the invention does not require an anode oxidation process, prevents protrusions that occur on the 1 μm film, prevents disconnection accidents in multilayer wiring, and efficiently increases performance. It forms a reliable conductive film and has a great effect on improving the reliability of semiconductor devices.

[Brief explanation of drawings]

FIGS. 1 to 3 are sectional views of the main parts of the process for explaining the conventional method, and FIGS. 4 to 7 are sectional views of the main parts of the process for explaining one embodiment of the present invention. In the figure, 11 is the semiconductor group #, 12 is the first 7/V
13 is a titanium nitride thin film, 14 is an insulating film 15
16 is a connection window, and 16 is a second aluminum wiring layer. 17 indicates a resist film. Figure 1 Figure 2 Figure 3 Δ

Claims (1)

[Claims] A semiconductor device comprising the steps of depositing an aluminum film on a substrate, further depositing a titanium nitride thin film, and then patterning the titanium nitride thin film and the aluminum film to form an MW. manufacturing method.