JPH03250628A - Semiconductor device - Google Patents

Abstract

PURPOSE:To strengthen adhesive strength to a base material and to prevent mutual diffusion of interconnection in a base by forming at least one layer of a base layer of a multilayer structure of a titanium nitride film. CONSTITUTION:Inner interconnection 30 and an electric insulting layer 40 are formed on a semiconductor substrate 10 through an insulating film 20 made of SiO2. Further, a contact hole is formed at the layer 40, a laminated base layer 50 made of a structure in which a TiN film 51, a Cu film 52 and an Au film 53 are sequentially laminated is then deposited, formed, and a solder bump 60 made of Pb61 and Sn62 is provided. In this case, the film 51 is deposited by a chemical vapor growing method. The film 51 is employed to increase the adhesive strength of the interconnection 30 and the layer 40 to the base material, and a salient electrode, electrode base in which mutual diffusions of the interconnection 30, the bump 60, the films 52, 53 are reduced, are realized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a semiconductor device, and particularly to an electrode base of a protruding electrode thereof.

[Conventional technology]

In connection methods such as the flip chip method and the tape carrier method, protruding electrodes are used as connection terminals for bonding a semiconductor chip and a wiring board such as a ceramic substrate or a resin substrate.

An example of the process for forming the protruding electrodes is to apply an electrical insulating film to a wafer on which internal wiring has been formed, and to apply IEf! using photoresist technology. A window for jL is opened, an electrode base is formed using a multilayer metal, and a protruding electrode such as a solder bump is formed on the seventh [ffl base].

A chip having this protruding electrode is known as chondral collapse bonding (CCB).

Ding, that is, this protrusion! When ffl is formed, it is installed with an electrode base interposed therebetween, and generally, as described above, a multilayer metal is used for the electrode base.

Various combinations are used for the base metal mli (BLM) of this bump. Cr/Cu/Au.

Examples include combinations such as T i /Cu /Au.

Incidentally, an example of a document that describes protrusions*poles and their electrode bases is RIC Mounting Technology J pi 75 and p 84 published by Kogyo Kenkyukai Co., Ltd. on January 15, 1980.

[Problem to be solved by the invention]

However, conventional multilayer metal electrode bases such as Cr
/Cu/Au, the BL
The lowermost Cr film of M is in contact with the above-mentioned type stunned l# film and the internal wiring, and is in contact with the internal wiring and Cu, Au.

It functions as a so-called barrier metal to prevent diffusion between the solder bumps and as an adhesive metal for the electrical film, and it is believed that the barrier metal and adhesive layer must play a major role. However, there are still problems in ensuring the reliability of electrical connections. In particular, when the wafer substrate surface has a high-step structure, the step-cutting ability (coverage) of the metal film at the bottom layer becomes poor, and problems with barrier properties and adhesion are increasingly caused. ing.

It is an object of the present invention to provide a technique that can eliminate the drawbacks of the prior art.

The above and other objects and novel features of the present invention include:
This can be determined from the description in the unknown specification and the attached drawings.

[Means to solve the problem]

A brief summary of typical inventions disclosed in this application is as follows.

In the present invention, a titanium nitride (TiN) film is used as the YLI base (
In particular, TiNjd, which was formed by chemical vapor deposition (CVD), was used in the lowermost layer in contact with the electrical kb edge film and the internal wiring.

[Effect]

The TiN film mentioned above has a superior effect of preventing diffusion between internal wiring and non-conducting metals, compared to Cr, which is used as the conventional lowermost gold metal. It also has excellent adhesion to membranes and internal wiring.

The electrical connection life of the protruding electrode is improved, and the reliability of the semiconductor device can be improved.

Furthermore, by forming the TiN film by the CVD method, it has excellent one-step liquid type properties, and the barrier properties and adhesive properties described above can be further improved.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. In the figure, an aluminum conductor wiring path (internal wiring) 30 is formed on a semiconductor substrate 10 holding one circuit element (not shown) through an insulating film 20 made of SiO, and a surface protective insulating layer (electrical An insulating layer) 40 is formed. These were created using Tatsuchi's semiconductor manufacturing technology. Furthermore, a contact hole ([polar window]) is provided in the insulating layer 40,
Next, TiNg51 with a thickness of 0.1 μm and CuP
After depositing and processing a laminated base layer 50 having a structure in which X52 is laminated to a thickness of 1 μm and an Au film 53 is laminated to a thickness of 0.2 μm.

The laminated base layer 50 and the solder bumps 60 were formed as follows, while providing the solder bumps 60 made of Pb61 and 5n62 and having a height of 80 μm. That is.

First, a semiconductor substrate 1 with contact holes provided in an insulating film 40 is prepared.
The TiN film 51, which is deposited on top of the substrate by chemical vapor deposition, is T + C at a substrate temperature of 400°C.
lt (108CCM) and NH, (700scch
0.3 to 0.4 Tor r with i+ as the reaction gas
The particles deposited in the plasma discharge are kept at σ).

The Cu film 52 and the ALl film 53 were deposited by a well-known resistance heating vapor deposition method. In processing the laminated base 1-, after providing a resist mask by ordinary photoresist processing, the uppermost Al film 53 and the intermediate Cu film 52 are processed.
5 Sweets processed by chemical etching with a mixture of iodine and ammonium iodide.

The TiN film was processed by CF and plasma etching.

Furthermore, the solder bumps 60 were formed by a lift-off method. This is done by forming a resist film with holes in the areas where bumpy installation is desired, and then using a resistance heating evaporation method to deposit Pb and Sn.
The solder is formed by sequentially depositing the bond, immersing it in a resist solution, and removing the resist and the solder on the resist. is then heated to a level above the melting points of Pb and Sn to dissolve Pb and Sn.

According to this embodiment, by employing the 1N film 51, the adhesion to the internal wiring 30 and the underlying material such as the electrical insulating layer 40 is strong, and the internal wiring: the solder bump 60, the Cu film 52 ．． Protrusions x′f with little interdiffusion with the Au film 53, etc.! iL, *It is possible to realize a solid base, which has the effect of improving the reliability of electrical connection, and since the formation of the TiN film 51 was carried out by the CVD method, it has excellent step Wt covering properties,
-1- It was possible to improve the above-mentioned adhesive force and to make it advantageous in terms of preventing mutual diffusion.

Although the present invention made by the present inventor has been specifically explained based on Examples, the present invention is not limited to the above-mentioned Examples, and may be modified in various ways without departing from the gist thereof.
There's no need to say that it's OJ Noh (・.

The electrode base for protrusion polarization according to the present invention can be applied to protrusion polarization in various fields such as flip chips and tape carrier tips.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

According to the present invention, the adhesive force with the base material is strong.

In addition, mutual diffusion with the underlying internal wiring is prevented, the 1wi connection life is improved, and the reliability of the semiconductor device can be improved.

[Brief explanation of drawings]

FIG. 1 is a schematic partial sectional view of a semiconductor device to which an embodiment of the present invention is applied. 10... Number of semiconductor bases, 20... Insulating film, 30...
Internal arrangement, 40... electrical insulation film (surface storage insulation film),
50... Base layer, 51... TiN film, 52... C
u membrane. 53...Au film, 60...Protruding electrode ()/unda bump), fi I -P b%62-8 n0

Claims (1)

[Scope of Claims] 1. An electrode window for forming a protruding electrode is provided in the electrical insulating film on the surface of the semiconductor substrate on which internal wiring is formed, and a base layer of a multilayer structure serving as a base for the protruding electrode is provided in the electrode window. In a semiconductor device in which a protruding electrode is formed through a base layer of the multilayer structure, at least one of the base layers of the multilayer structure
A semiconductor device characterized in that the layer is composed of a titanium nitride film. 2. A claim in which the titanium nitride film is located at the bottom layer in contact with the electrical insulating film and the internal wiring, and the film is formed by chemical vapor deposition, which is a film formation method using chemical reactions in the gas phase. Item 1. The semiconductor device according to item 1.