JPS5835927A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To enhance the evaporating speed, while eliminating contamination, and to make as suitable for automation when an insulating film of a semiconductor device is to be formed by a method wherein a crucible is arranged under a substrate to constitute the device, high melting point conductors are put therein, the conductors are heated by electromagnetic induction, and an insulating material coming in contact therewith is made to be evaporated and to be adhered on the substrate. CONSTITUTION:Tungsten blocks of the high melting point conductors are filled up in the bottom part of the crucible 1 consisting of pyrolytic boron nitride and are made as the heating conductors 2, and the evaporating matter 3 of SiO2, etc., to form the insulating film is filled thereon. Then a wafer 5 to be evaporated is arranged at the upper part of the crucible 1 interposing the prescribed interval between them, and a high-frequency current of 35-55kHz is made to flow in a work coil 4 wound around the outside circumference of the crucible 1 holding the circumference thereof at the vacuum of 10<-6>-10<-7>Torr. Accordingly eddy currents are made to be generated in the conductors 2, the matter 3 is made to be evaporated by Joule heat thereof, and the insulating film is adhered on the surface of the facing wafer 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming an insulating film in a semiconductor device manufacturing ticket.

Various methods are applied to forming an insulating film of a semiconductor device depending on the objective (9) conditions.

For example, a thermal oxidation method is generally used to form a field oxide layer formed on a silicon substrate, and also when forming a gate oxide film for an MO8 field effect transistor, properties such as film thickness and withstand voltage are uniform. However, the thermal oxidation method is naturally limited in its application and has a wide range of application.
When the apour depo-sitlon method is applied to the formation of insulating films, various insulating films can be obtained at deposition temperatures considerably lower than the melting point of the insulating film to be grown. This method has advantages such as higher purity and stable characteristics of the insulating film formed compared to the conventional method, but there are problems such as uniformity of the formed film and slow JI growth rate.

The sputtering method also has the advantage of low deposition temperature and the ability to easily form various insulating films by changing the target material, but compared to the CVD method, the purity of the formed film is lower, and the speed is lower. Although high-frequency sputtering has a faster growth rate than DC sputtering, it still lacks the growth rate.
) method has problems such as poor stoichiometry of the formed insulating film and radiation damage to the product, and is not suitable as a method for manufacturing semiconductor devices.

Furthermore, resistance heating evaporation methods that use boat-shaped heaters made of high-melting point metals such as tantalum and molybdenum are likely to be subject to limitations in the capacity of the evaporation source, and are often accompanied by evaporation of the metal forming the heater. QAlso, as a resistance heating vapor deposition method that allows high-speed vapor deposition such as 810 and large capacity, Drumhe#e
There are methods such as r, but the current is large and there is a risk of evaporation and contamination of resistor metal such as tantalum.

On the other hand, in semiconductor device manufacturing, each process is organized into a series of lines, and work errors caused by workers,
Automation of the manufacturing process is being promoted in order to prevent yield declines caused by handling scratches, contamination marks, minute foreign objects, etc., and to economically produce high-quality ICE with high integration density for semiconductor devices. has been done. However, the CVD method, sputtering method, etc. have a large limitation due to poor adaptability to automation or line organization in terms of the time required for the film forming method.

SUMMARY OF THE INVENTION It is an object of the present invention to address the above-mentioned problems of known manufacturing methods with respect to Ii & film formation for semiconductor devices, and to provide a manufacturing method that is especially adaptable to automation or line organization.

The above object of the present invention is achieved by heating a high melting point conductor such as tungsten by electromagnetic induction, and evaporating the insulating material in contact with the conductor to adhere it to the target surface.

The present invention will be specifically described by way of embodiments with reference to the drawings.

The drawings are cross-sectional views showing embodiments of the present invention. In the figure, 1 is a crucible, and in this example, the crucible 1 has a diameter of about 35 m, a depth of about 5 Qi+i, and a wall thickness of 0.5111 m.
P B N (P)'rotic Boron N1
tr1de) yosi naru. In this method, a tungsten block was filled at the bottom of the heating conductor 2.The heating conductor 2 was then filled with an evaporated substance 3 to form an insulating film. 3 is silicon monoxide (S10) 0 In this state, place 1 in the work coil 4 and place the wafer 5 to be deposited in the crucible.
Keep it at a distance of about 150 to 300 meters above, and
Maintain a vacuum of 0 to 10 torr, work coil 4
By applying a power of 5 JftW at a frequency of 35 to 55 kHz, deposition was carried out for about 1 minute, and the thickness was about 1.0/1.
siogt of fFl was formed.

In the heating of the present invention, an eddy current is generated in the heating conductor 2 by electromagnetic induction from the current of the work coil 4, and the evaporative substance 3 is heated by the heating conductor 2 whose temperature has increased due to Joule heat caused by the eddy current until it evaporates. 0 In this process, it is necessary for the "rutsuwa" 1 and the heating conductor 2 to have sufficient heat resistance, so that they do not evaporate or dissolve in the evaporated substance 3 during this process. It must not cause any chemical change. In the present invention, since the shape of the heating conductor 2 does not require special heat treatment as in the Dramheller method and other resistance heating methods, it is possible to use tungsten, which has a higher melting point than molybdenum or tantalum. In addition, the shape of the evaporated substance 3 is not restricted so much (in order to perform the evaporation action uniformly, the evaporated substance must be in a powder state,
In particular, fine particles of #100 or less are desirable.

Also in this embodiment, the evaporated substance 3 is 20 to 3Q in advance.
Although the capacity is larger than that of the force oMM deposition method using the boat-shaped resistor described above, it is also easy to automatically supply SiO during the vapor deposition process. The deposition rate of
am/- is 50 to 250 times faster than directly. Furthermore, it is easy to continuously supply the wafer to be evaporated 5, and it is adaptable to connection with other processes.In addition, the wafer to be evaporated can be rotated during evaporation as necessary. It is easy to use, and it is possible to ensure the uniformity of the insulating film formed. Note that the sputtering method or the E-B gun method does not use force or radiation that does not use collisions of ions or electron beams. No damage to the product occurs and no separation is obtained by the present Ij110 method.
For example, at a thickness of 150 nm, PSG (Phosphor 51
It has excellent adhesion to silicon, silicon dioxide (SlO), tPSG, or aluminum, and has a high density. It is particularly suitable for interlayer insulating films or insulating films because cracks do not occur compared to tungsten tubes. material t
- It forms an insulating film for semiconductor devices by evaporating it and depositing it on the target surface.The evaporation speed is fast, there is less damage to the product, and it is suitable for automation or line transfer. In addition, the 810 insulating film obtained by the method of the present invention has a high withstand voltage, excellent adhesion, and does not cause cracks, making it suitable for layer insulation or galvanized insulation glands. There is.

[Brief explanation of drawings]

The drawings are cross-sectional views showing embodiments of the present invention. In the figure, 1 is a melting pot, 2 is a heating conductor, 3 is an evaporation material, 4 is a work coil, and 5 is a wafer to be evaporated. 5 4

Claims (2)

[Claims] (1) A method for manufacturing a semiconductor device, which comprises heating a high melting point conductor by electromagnetic induction to evaporate an insulator in contact with the conductor to form an insulating film on a substrate. (2) The method of manufacturing a semiconductor device according to claim 1, wherein the insulator is silicon monoxide.