JPS60262442A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To shorten a through-hole boring process by boring openings to an alumina layer as first layer wiring and an inter-layer insulating film through one- time ion milling and attaching and forming a second layer metal through sputtering in a device. CONSTITUTION:First layer Al wiring 13 and a thick alumina film 12 and a thin alumina film 12' on the wiring 13 through an anodizing method are formed onto a semiconductor substrate 11. An inter-layer insulating film 14 is grown on the films 12, 12', and a photo-resist 16 for forming a through-hole is attached and patterned. The film 14 and the film 12' are tapered and bored through one-time ion milling by an ion milling device. The resist 16 can also be removed through etching at the same time. Targets are exchanged and Al is attached through sputtering as a second layer metal in said device, the photo-resist is patterned, and a second layer Al wiring 15 is formed through etching. Accordingly, a manufacturing process can be shortened while a breaking at the stepped section of the second layer Al wiring can be prevented.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a method for manufacturing a semiconductor device, and in particular to a flexible alumina layer on a first-layer wiring board and interlayer insulation when the first-layer wiring is formed by an anodizing method. This article relates to the method of opening holes in the membrane and the method of adhesion of the second layer of wire-resistant metal r.

(Prior art) A conventional method of opening through holes in the interlayer insulating film of a semiconductor device and connecting the first and second layer wiring is shown in FIGS. 3(a) to 3(d). I will explain.

First, as shown in FIG. 3 (al), aluminum 3 is attached to the semiconductor substrate 1 for the first layer l!
Then, a 6i1 line is formed using an anodic oxidation method. Patterning is performed using photoresist (64'j) to open holes in the thin alumina film 2' on the surface of the first layer of aluminum wiring.

Next, as shown in FIG. 3(b), an interlayer insulating film 4 is grown on the surface of the semiconductor substrate along the etched edges of the alumina film 2', and patterned with photoresist 6' to form holes.

Next, as shown in Figure 3 (C), the insulation layer 4 is wet-etched to form holes, and a second layer of aluminum wiring layer 5 is deposited on the semiconductor substrate, after which wiring is formed. For this purpose, repatterning is performed using photoresist 6''.

Next, as shown in FIG.
By removing ", a semiconductor device with a two-layer wiring structure can be obtained.

The semiconductor device obtained as described above has the following problems.

(1) The process becomes complicated because it requires a step of opening a hole in the round alumina film on the first layer of aluminum wiring and a step of opening the hole again at the same location after the growth of the interlayer insulating film.

(2) Because holes are formed in the thin alumina layer and the insulating film between the layers by wet etching, and if there is a misalignment in patterning the two layers of photoresist, the steps of the through holes will become quite steep. After the aluminum wiring is attached, a break occurs at the through-hole area.

(Object of the Invention) The object of the present invention is to provide a method for manufacturing a semiconductor device that eliminates the above-mentioned drawbacks, shortens the through-hole drilling process, and prevents breakage at the through-hole portion of the second layer aluminum wiring. It is about providing.

(Structure of the Invention) A method for manufacturing a semiconductor device according to the present invention is a method for manufacturing a semiconductor device having a two-layer wiring structure, in which a first layer wiring and a second layer wiring are connected by a through hole formed in an interlayer insulating film. , the process of forming a tapered hole in the thin alumina layer on the first layer wiring and the interlayer insulating film by one-time ion milling, and then changing the target in the same equipment and forming the aluminum as the second layer metal. It is composed of sputtering ((a step of forming an adhesion layer).

(Example) Examples of the present invention will be described below with reference to the drawings. FIGS. 1(a) to 1(C) are cross-sectional views shown in the order of steps to explain one embodiment of the present invention, and the second section (a)
, (b) and (c) are explanatory diagrams of ion milling. 1 Figure 2 (a) is an explanatory diagram of the principle of ion milling, and Figure 2 (fb) is an illustration of the etching of an interlayer insulating film of a semiconductor substrate by ion milling. Explanatory diagram of the inside of the device, Figure 2 (C
) 4- is an explanatory diagram of the inside of the apparatus when spun aluminum onto a semiconductor substrate by ion milling.

First, as shown in FIG. 1(a), the first layer of aluminum wiring 13 is formed on the semiconductor substrate bl.
is a thick alumina film formed by anodic oxidation, 12'
is a thin alumina film on aluminum wiring. Next, after an interlayer insulating film 14 is grown on the alumina film 12, 12', a photoresist 16 for forming through holes is deposited and patterned.

Next, as shown in FIGS. 2A and 2B, the semiconductor substrate 25 on which the patterning of the photoresist 16 has been completed is set in the holder 18 in the ion milling device 27, and the holder 18 is tilted at a 00 angle as shown in the figure. The wafer is ionized, and the wafer is exposed to the wafer.During the ionization process, the holder 8 is rotated relative to the normal line of the holder.By rotating the holder 8, variations in etching within the wafer and within the holder can be reduced. You can do less.

Since ion milling is physical etching using Ar 9, by appropriately selecting the film thickness of the photoresist 16 and tilting the holder, it is possible to achieve
) It is possible to perform etching through the taper kh with the through hole t, and at the same time, the photoresist 16 can also be removed by etching 1. During etching, the shutter 22 of the aluminum target of the ion milling device is kept closed.

Next, as shown in FIG. 2(c), while the semiconductor substrate 25' with the through-holes is set in the holder 18, the ion source 2 and the grid 23 are tilted at an angle of θ0. 9 aluminum targera l-2
Point towards 0. Next, when the shutter 22 of the aluminum target 20 is opened, Ar 19 collides with the aluminum target 20, whereby aluminum atoms 24 are ejected and propagated into the fastening body plate 25'. After the aluminum has been deposited for a predetermined period of time, photoresist patterning is performed to take out the 2m wiring, and then etching is performed to form the second layer of aluminum wiring 15 as shown in Figure 1(C). As a result, according to the present invention, a semiconductor device having a 6-two-layer wiring structure can be obtained.

(Effects of the Invention) As explained above, according to the present invention, after the first layer wiring is formed on a semiconductor substrate, a through hole can be formed in an interlayer insulating film by ion milling to form a taper and then etched in a single process. Furthermore, aluminum metal for second layer wiring can be deposited by sputtering in the same device.

Therefore, it is possible to prevent breakage of the second layer aluminum wiring, and to significantly shorten the manufacturing process.

[Brief explanation of drawings]

FIGS. 1(a) to (c) are cross-sectional views shown in the order of steps to explain one embodiment of the present invention, and FIGS. 2(a) to (c) are sectional views of the ion-soring process used to implement the present invention. Figure 2 (a) is an explanatory diagram of the principle, Figure 2 (bl is an explanatory diagram of the inside of the ion milling apparatus during ion milling of an interlayer insulating film on a semiconductor substrate, and Figure 2 (C1 is an illustration of the inside of the ion milling apparatus during ion milling of an interlayer insulating film on a semiconductor substrate). Fig. 3 is an explanatory view of the inside of the apparatus during sputtering of aluminum onto a substrate, and Figs.・・Semiconductor substrate, 2,12°・Alumina, 2′, 12′・・・・・・Thin alumina film on first layer aluminum wiring, 3,13・・・・First layer aluminum wiring, 4 , 14... Insulating film, 5,
15... Second layer aluminum wiring, 6.6',
6", 16... photoresist, 18...
・Holder for semiconductor board set, 19...Ar
Ion, 20... Aluminum target, 2
1... Ion source, 22... Aluminum target shutter, 23... Grit), 24... Aluminum atom, 25...
... Semiconductor substrate with through holes, 25'.
...Semiconductor substrate with through holes, 26.
...Exhaust port, 27°°°゛°° Milling device body・5”

Claims (1)

[Claims] Layer the connection between the first layer wiring and the second layer wiring, and open a hole in the insulating film.
In the 99 manufacturing method of a semiconductor device with a two-layer wiring structure using the formed through-hole, the thin alumina T- layer on the first layer wiring and the interlayer insulating film are removed by one ion milling.
A method for manufacturing a semiconductor device, comprising the steps of forming a hole with a taper, and further changing the target to 9 in the same apparatus and depositing aluminum as a second layer metal by sputtering.