JPH05152280A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent hillock and disconnection of aluminum when an aluminum wiring is already formed in a semiconductor chip which is a foundation substrate by depositing an insulating film while raising a formation temperature from a specified value. CONSTITUTION:A semiconductor chip is put in a reaction filter of a CVD device which is heated to 150 deg.C. It is left as it is for 1 to 20min. After the temperature of a wafer becomes constant, reaction gas (SiH4-NH3-N2O) is introduced and, at the same time, the temperature is made to rise at a rate of 150 deg.C/min and held at 300 deg.C after 10min. An Si-O-N film is made to grow to a thickness of about 200nm while the temperature rises up to 300 deg.C from 150 deg.C, and is made to grow to the thickness of about 800nm at 300 deg.C. Since the Si-O-N film formed in this way has little stress in a lower layer and is dense in an upper layer, it is possible to prevent generation of aluminum hillock and to realize good passivation efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device, and more particularly to a method of forming an insulating film by a plasma CVD method.

[0002]

2. Description of the Related Art Conventionally, when a cover insulating film or the like is deposited on a semiconductor chip having metal wiring by a plasma CVD method,
The formation temperature was kept constant and the film was formed.

[0003]

In this conventional process for forming a film at a constant temperature, the production temperature is usually set to a relatively high value of around 300 ° C. Therefore, the semiconductor chip of the base substrate is made of an aluminum-based metal. When the wiring is already formed, hillocks of aluminum are generated, and if severe, disconnection occurs, resulting in a decrease in yield and quality.

According to the present invention, there is provided a method of manufacturing a semiconductor device including a step of depositing an insulating film on a semiconductor chip having metal wiring formed thereon by a plasma CVD method, while increasing a generation temperature from a predetermined value. This is to deposit an insulating film.

[0004]

Next, an embodiment of the present invention will be described.

First, as shown in FIG. 1A, a semiconductor in which elements such as transistors (not shown), a silicon oxide film 2 (a field oxide film, an interlayer insulating film, etc.) and an aluminum wiring 3 are formed on a P-type silicon substrate 1. Prepare a chip (actually a wafer) and heat it to 150 ° C
It is placed in the reaction furnace of the plasma CVD apparatus. The reaction gas (SiH ₄ —NH ₃ —N ₂ O) was introduced after the temperature of the wafer became constant for 1 to 20 minutes, and at the same time, as shown in FIG. 2, at a rate of 15 ° C./min. The temperature is raised and kept at 300 ° C. after 10 minutes. Temperature is 15
A Si—O—N film is grown to a thickness of about 200 nm between 0 ° C. and 300 ° C., and a thickness of about 800 nm is grown at 300 ° C. However, the flow rates of Si ₄ gas, NH ₃ gas, and N ₂ O gas are each 1000 cc / min,
The pressure is 300 cc / min and 250 cc / min, the furnace pressure is 0.35 Torr, the frequency is 50 kHz, and the microwave power is 1.0 W.

The Si-O-N film 4 thus formed has less stress in the lower layer and is dense in the upper layer.
It prevents generation of aluminum hillocks and, at the same time, has an excellent passivation effect.

The deposition of the insulating film is not limited to Si-O-N, but Si-N or Si-O may be used. Further, it may be either an interlayer insulating film or a cover insulating film for use.

[0008]

As described above, in the semiconductor, the deposition of the insulating film is started at a low temperature of about 150 ° C., and the temperature is gradually raised to about 300 ° C. to form a film. The upper layer has the effect of preventing aluminum hillocks and disconnection by forming a dense film quality and capable of manufacturing a highly reliable semiconductor device with a high yield.

[Brief description of drawings]

1A to 1C are cross-sectional views in order of the processes, which are illustrated in FIGS.

FIG. 2 is a graph showing a temperature schedule in one example.

[Explanation of symbols]

 1 P-type silicon substrate 2 Silicon oxide film 3 Aluminum wiring 4 Si-ON (silicon oxynitride) film

Claims (1)

[Claims] 1. A method of manufacturing a semiconductor device, comprising a step of depositing an insulating film on a semiconductor chip having metal wiring formed thereon by a plasma CVD method, wherein the insulating film is deposited while increasing a generation temperature from a predetermined value. And a method for manufacturing a semiconductor device.