JPS6062115A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To bond both an inorganic insulator and metals and a metal excellently by using the evaporating source metal containing phosphorus. CONSTITUTION:An Al film 2 as an ohmic contact is formed to one part of the surface of a Si base body 1. The base body 1 and the surface of the film 2 are coated with a SiO2 film 3, and one part of the film 3 on the film 2 is not formed on a window. A Cr-Cu composite film 4 is bonded with the film 2 not coated with the film 3, and extended and bonded on the peripheral film 3. An evaporating source Cr for the film 3 contains phosphorus. When Cr and Cu for the film 3 are evaporated, phosphorus is evaporated together with Cr, the surface of the layer 3 is reduced while also being combined with Cr, Cr and Cu fill roles such as an inverter for the film 3 and a Cr layer, and adhesive force to the film 3 is ensured. The deacidifying action of phosphorus also contributes to adhesion between the film 2 and the Cr layer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for physically vapor depositing a metal film on a semiconductor substrate.

[Background of the invention]

A semiconductor device has electrodes mainly made of metal for connection with an external circuit. The electrode needs to have ohmic contact with the semiconductor substrate. The planar structure varies widely depending on the form of the semiconductor substrate to be bonded, and is not limited to simply stacking metal on a semiconductor substrate.
For example, at the outer periphery of the electrode pattern, an oxide film, an imaging film, an insulating film such as glass, or an 8IPO film surrounding the electrode forming semiconductor part.
There is a shape that extends over the 8th film, or a shape that extends over the insulating film in order to provide an external connection part in a part remote from the electrode-forming semiconductor part. Problems in manufacturing such a structure include adhesion to the semiconductor substrate, insulating film, and 5IPO8 film, and in the case of a composite structure, adhesion between different metals. In order to deal with this problem, the combination of metals is selected based on ``compatibility'', which takes into account the difficulty of reactions between the metals and the form of the reaction, and when forming on an insulating film, for example, inorganic For the membrane, measures are taken such as selecting a metal that easily combines with oxygen. Despite such considerations, these electrodes
Weak or weak adhesion and excessive electrical resistance often occur, causing problems in the manufacture of semiconductor devices. It has been found that many of the causes of such problems are due to the oxidation of surface oxides on the part to be deposited at the time of physical vapor deposition of the metal and the oxidation of the evaporated metal during deposition.

[Purpose of the invention]

The present invention was created in order to overcome the drawbacks of the above-mentioned prior art, and aims to solve the problems of metal interlayers, semiconductor substrates, inorganic insulating films, and 5IPO8 constituting a composite electrode.
It is an object of the present invention to provide a method for manufacturing a semiconductor device that can bond a film and an electrode metal well by physical vapor deposition.

[Summary of the invention]

The present invention takes advantage of the property of phosphorus to easily form compounds with other atoms, and is characterized by the fact that the evaporation source metal contains phosphorus.

[Embodiments of the invention]

Hereinafter, the present invention will be explained by examples.

In FIG. 1, 1 is a silicon substrate;
There is an aluminum film 2 on a part of the surface as an ohmic contact. The 5j02 film 3 covers the surface of the silicon substrate 1 and the surface of the aluminum film 2, and a part of the 5102 film 3 on the aluminum film 2 does not exist in the form of a window. The aluminum film 2 not covered by the 5j02 film 3 is coated with chromium.
The copper composite film 4 is adhered and extends onto and adheres to the surrounding 5iOz film 3. This structure is a ball-limiting metallurgy in which solder balls are formed on a chromium-copper composite film 4 and subjected to controlled collapse assembly. FIG. 2 depicts a part of FIG. 1 in more detail, and the aluminum film 2 has a thickness of 3 μm.
The thickness is 5 μm. Chromium-copper composite film 4 is 0.15μ
It consists of two layers: chromium 41 with a thickness of m and copper 42 with a thickness of 0.65 μm.

- In the example, the chromium layer 41 and the copper layer 42 were deposited by vacuum deposition. The source chromium contains 0.1% by weight of phosphorus. Phosphorus-containing chromium is produced by mixing phosphorus or chromium containing phosphorus into molten chromium. Chromium was evaporated to a thickness of 0.1 μm by electron beam heating, and then chromium was deposited to a thickness of 0.05 μm.
Copper equivalent to a thickness of 0.5 μm was also deposited, and the copper was bonded to a thickness of 0.6 μm.
Deposited to a thickness. According to the above vapor deposition, phosphorus evaporates together with chromium, reduces the surface of the 5LOz layer 30, and at the same time combines with chromium, as if SiO2 film 3 and chromium layer 4
1, and secures adhesive strength to the 81Ch film 3. The deoxidizing effect of phosphorus also contributes to adhesion between the aluminum film 2 and the chromium layer 41. Although the aluminum film 2 is cleaned by acid treatment before vapor deposition, it combines with oxygen in the air to form an alumina film. As phosphorus is deposited along with chromium, it combines with the alumina to form a slug, leaving surfaces uncovered by alumina and providing direct contact between aluminum and chromium.

In another example, the source steel contained 0.2% by weight phosphorus.

The evaporation source steel was selected after analyzing low-quality commercial products. Chromium and copper were deposited in the same manner as in the previous example. In the case of this example, when copper is deposited, phosphorus evaporates first due to its ease of evaporation, and a large amount of phosphorus is incorporated into the chromium side. Phosphorus is deposited on top of 0.1 μm chromium,
It can exert a getter effect to reduce the cr-o produced by combining with residual oxygen in the vacuum chamber during chromium deposition.

Therefore, the chromium adheres to the portion in contact with the 5i02 film 3 in a form that shares oxygen, resulting in ideal adhesion. This example shows a case where phosphorus acts indirectly through a metal film.

Examples have been given for chromium and copper, but phosphorus is aluminum, titanium, vanadium, and nickel.

Since it reacts with most metals used as electrodes, such as cobalt, iron, silver, gold, molybdenum, and tungsten, to form phosphides, this book does not apply to these other metals, regardless of the examples. It goes without saying that the invention is applicable, and physical vapor deposition, sputtering, and ion blating methods other than vacuum deposition can also be used.

Furthermore, even if a composite structure is not adopted, if the vapor deposition source of the metal that becomes the electrode contains phosphorus, after vapor deposition, the metal can be applied to the semiconductor substrate or the insulating film provided on the semiconductor substrate.
Alternatively, it shows good adhesion with the 5IPO8 film.

Further, when a composite structure is employed, it is not necessary to include phosphorus in all the vapor deposition source metals, and only metals with low adhesion may contain phosphorus.

〔Effect of the invention〕

As described above, according to the present invention, by using an evaporation source containing phosphorus, an inorganic insulator and a metal can be bonded to each other well.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a semiconductor device obtained according to an embodiment of the present invention, and FIG. 2 is a partially enlarged view of FIG. 1.

Claims (1)

[Claims] 1. Manufacturing method f of a semiconductor device in which metal is deposited on a semiconductor substrate
A method for manufacturing a semiconductor device, characterized in that the vapor deposition source metal contains phosphorus. 2. In claim 1, a metal film, an insulating film, or a 5IPO8 film is provided on a part of the semiconductor substrate, and a metal containing phosphorus is deposited on these films or on the semiconductor substrate. A method for manufacturing a semiconductor device characterized by: 3. Percentage of Claims Claim 1 provides a semiconductor device characterized in that the evaporation source metal containing phosphorus is deposited on a semiconductor substrate by vacuum evaporation, snobbing, or ion blating method. Manufacturing method. 4. In claim 1, the vapor deposition source metal is any one of aluminum, chromium, titanium, sodium, nickel, cobalt, iron, copper, silver, gold, molybdenum, and tungsten, or a component containing these. 5. In claim 2, the insulating film is an inorganic insulating film such as a semiconductor oxide film, a nitride film, or glass. Manufacturing method for semiconductor devices.