JPH0541373A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To shorten the process period of the title manufacture and to reduce the cost of the title manufacture when a protective film for a semiconductor device is formed. CONSTITUTION:Aluminum wiring 8 is patterned; after that, a photoresist 10 is coated, exposed to light and developed; and an electrode part is opened. After that, ions are implanted at a high dose; the surface of the resist is hardened; and the resist is used as a protective film as it is. As a result, a process is simple as compared with the formation of a protective film in conventional cases, the process period of the tile manufacture can be shortened and the cost of the title manufacture can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a protective film for preventing corrosion of wiring and deterioration of devices.

[0002]

2. Description of the Related Art A manufacturing flow up to FIG. 2A for explaining a conventional method for forming a protective film of a semiconductor device will be briefly described with reference to FIG. First, well regions (P well, N well) to be the P type region 2 and N type region 3 necessary for forming a MOS transistor are formed. Further, in order to form an element isolation region, a thick oxide film region 4 (field) and a diffusion layer region for forming a MOS transistor surrounded by the thick oxide film region 4 are formed by a local oxidation method. Next, the surface of the wafer corresponding to the element region is oxidized to form a gate oxide film, and a polycrystalline silicon film to serve as a gate is deposited thereon. Next, the gate portion 5 is left and other portions are etched, ion implantation is performed using the gate portion and the field oxide film as a mask, and heat treatment is performed to form the diffusion layer 6. After that, an interlayer film 7 for maintaining the insulation between the wirings is deposited, an etching process for contact hole formation for connecting the wiring to the diffusion layer is performed, and aluminum 8 to be the wiring is deposited, and patterning is performed. Next, a protective film 9 is grown as shown in FIG. 2B, a photoresist is applied as shown in FIG. 2C, and exposure and development are performed for patterning. Then, as shown in FIG. 2D, the protective film in the portion to be the electrode portion is etched, and finally the photoresist is removed as shown in FIG. It was

[0003]

In the past, steps such as protective film growth photoresist coating / patterning, protective film etching, and photoresist removal were required to form a protective film. It was difficult to reduce the construction period and cost.

An object of the present invention is to achieve a shortened construction period and cost reduction in forming a protective film for a semiconductor device.

[0005]

In order to achieve the above-mentioned object, a method of manufacturing a semiconductor device of the present invention is to deposit a photoresist and directly apply a photoresist on the aluminum after patterning to open an electrode portion. Expose and develop. After that, the photoresist is hardened by high dose ion implantation, and the resist itself is used as a protective film.

[0006]

The present invention will be described below with reference to the drawings. 1A to 1D are cross-sectional views of a semiconductor device in the order of steps for explaining an embodiment of the present invention. FIG. 1A shows a state in which patterning of aluminum to be wiring is completed. From this state to the conventional method, a film serving as a protective film was grown, but in the present invention, as shown in FIG. 1B, a photoresist is applied to the entire surface of the wafer to open the electrode portion. Perform exposure and development. After this, Fig. 1 (C)
As shown in, a high dose ion implantation is performed on the photoresist. The photoresist, which is an organic substance, has its surface burned and hardened by this high-dose ion implantation. Regarding this ion implantation, it is necessary to pay attention to the type of implanted atoms. For example, when a metal atom is implanted into a resist, it may cause a leak or cause deterioration of the device. Implanting atoms of the insulator is appropriate. Also, the dose amount must be controlled so that the conductivity of the aluminum electrode portion is not impaired and the resist is sufficiently cured. For example, when implanting silicon atoms, 1 × 10 ¹⁸ / cm ^{-3 -1}
There is an optimum point in the range of × 10 ¹⁴ / cm ^-3 . Of course, this value may increase or decrease depending on the type of resist. The photoresist thus obtained has sufficient resistance as a protective film, and has the same strength and protective ability as the conventional protective film against mold encapsulation in the assembly process.

[0007]

As described above, in the method for manufacturing a semiconductor device of the present invention, the process of growing a protective film after aluminum wiring and etching is omitted, and the photoresist itself is applied as the protective film, so that the manufacturing period is shortened. , It has the effect of cost reduction.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a semiconductor device shown in the order of steps for explaining an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a semiconductor element, which is shown in order of steps for explaining a conventional method for manufacturing a semiconductor device.

[Explanation of symbols]

 1 Semiconductor Substrate 2 P Well 3 N Well 4 Field Oxide Film 5 Polycrystalline Silicon Gate 6 Diffusion Layer 7 Interlayer Insulation Film 8 Aluminum Wiring 9 Protective Film 10 Photoresist

Claims (1)

[Claims] 1. A method of manufacturing a semiconductor device, comprising: a step of forming aluminum wiring; a step of applying a photoresist on a semiconductor substrate having the aluminum wiring formed thereon; and a step of exposing and developing the photoresist to form a pad portion. A method of manufacturing a semiconductor device, comprising: a step of forming a hole; and a step of curing the photoresist itself, which has been opened in the pad portion, and using the cured photoresist as it is as a protective film.