JPS59194439A - Method for forming pattern of semiconductor device - Google Patents

Abstract

PURPOSE:To accurately form a pattern without producing dimensional conversion difference by selectively emitting an accumulated layer and altering the etching velocity. CONSTITUTION:Radiation 13 of a laser light or the like is selectively emitted to a passivation film 12 in accordance with the prescribed pattern. At this time, the part 14 emitted by the radiation 13 of the film 12 is equivalently heat treated to increase the denseness of the part 14. As a result, a difference occurs at the etching velocity between the part 14 emitted by the radiation 13 and the part 15 not emitted, and the etching velocity of the latter becomes one/several tens of that of the former. Accordingly, when the film 12 is etched after the emitting, the part 14 remains, while the part 15 is removed by etching. As a result, the pattern of the film 12 is completely formed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a method for forming a pattern in a semiconductor device without using a renost layer.

(Description of Prior Art) In general, when manufacturing a semiconductor device, a so-called masking technique is used to form various regions, wiring patterns, and other constituent parts required for the semiconductor device.

FIG. 1 is a process diagram illustrating a patterning process of a deposited layer such as an insulating thin film formed on a base layer such as a semiconductor layer or a metal thin film, and particularly, as an example, a patterning process of a passivation film. In the conventional example shown in FIGS. 1A to 1C, first, as shown in FIG.
A passivation film 2 is formed thereon. Usually, a film of phosphosilicate glass (PSG) or silicon nitride (S13N4) is used as this passivation film. When pattern forming this NOP horn veinyon film, the first
As shown in FIG. This resist layer 3 is selectively etched to leave the resist layer 3 at predetermined locations.Then, the remaining resist layer 3
using the lower 7J? as a mask layer. Selective etching of the blade film 2 is performed.

In this way, in the conventional patterning process, the resist layer e
Since the passivation film, which is an insulating film, is etched using a tE cloth as a mask, there are drawbacks such as problems in adhesion between the insulating film and the resist layer, and side etching. Also, using a resist layer,
In the process of patterning the resist layer using ultraviolet rays,
There is a drawback that accurate turning cannot be performed because of optical effects such as light diffraction and multiple reflections that cause a difference in dimensional conversion between the shifted mask and the master turn molded Renost mask. Furthermore, since the resist layer used is an organic material, it must be thoroughly cleaned before proceeding to subsequent steps, which has the drawback of increasing the number of steps and manufacturing costs.

(Objective of the Invention) An object of the present invention is to provide a method of patterning a semiconductor device without using a resist layer, which eliminates the drawbacks of the conventional patterning method described above.

(Structure of the Invention) In order to achieve this object, according to the present invention, first, a deposited layer to be formed into a R-turn is formed on the surface of the base layer, and then this deposited layer is selectively irradiated with radiation. The method is characterized in that the deposited layer is etched to form a pattern by utilizing the difference in etching rate between the portions of the deposited layer that are irradiated with the radiation and the portions that are not.

(Description of Examples) Examples of the method for forming a pattern of a semiconductor device of the present invention will be described below with reference to the drawings.

2A to 2C are process diagrams showing an embodiment of the pattern forming method according to the present invention, 11 is a base layer, for example, a semiconductor layer comprising various semiconductor circuit elements formed on a semiconductor substrate, 12 is a passivation layer In the film, 13 is a radiation such as a laser beam or an electron beam, 14 is a passivation portion that is irradiated with this radiation, and 15 is a passivation portion that is not irradiated with radiation.

First, as shown in FIG. 2A, a passivation film 12 is deposited as a deposited layer on the semiconductor layer 11 on which semiconductor circuit elements are formed by a conventionally known method. Next, when patterning this passivation film, a second
As shown in FIG.
selectively irradiates. At this time, the portion 14 of the noxivation film 12 that has been irradiated with radiation has not been subjected to the same heat treatment, and therefore the tightness of the portion 14 is increased. As a result, there is a difference in the etching speed between the portion 14 that has been irradiated with radiation and the portion 15 that has not been irradiated, and the etching speed of the former portion 14 is several tenths of the etching speed of the latter portion 15. It becomes extremely slow. Therefore, after radiation irradiation, this mother passivation film 12
When the entire xt L etching process is carried out, the portion 14 that has been irradiated with radiation remains as shown in FIG. is completed.

l according to the invention? (In the turn forming method) When the deposited layer 12 as an insulating layer is made of, for example, phosphosilicate glass (PSC) and laser light is used as radiation, the carbon dioxide gas laser is easily absorbed by the deposited layer, which is the PSC film. It is suitable to use. In this case, the energy of the laser beam used is approximately Q, 5 J/cm2 to 10 J/CJn
A range of 2 is preferable. In order to effectively utilize energy by taking into consideration the multiple reflection of laser light on the PSC film, more effective heat treatment can be performed by appropriately selecting the thickness of the PSC film in advance.

Also, an electron beam may be used as the radiation instead of a laser beam. In this case as well, the energy equivalent to the energy of the laser beam is
By making the electron beam 'z of radiation incident on the PSG film 12, it is possible to produce a difference in the etching rate of the PSC film before and after irradiation, as well as in the case of laser light.

In this way, the etching rate of the PSC film irradiated with radiation was reduced to several tenths of that of the PSC film that was not irradiated, that is, before irradiation, and the subsequent etching treatment of the PSC film reduced the etching rate of the PSC film.・Can perform turn forming efficiently and accurately.

Furthermore, it is possible to effectively set the thickness of the PSG film to be deposited by considering in advance the difference in etching speed during the etching process and predicting the thickness of the PSG film to be left in advance. Description: The present invention is applicable to turn forming of semiconductor devices, and increases the tightness of a deposited layer to be patterned on a base layer by selectively irradiating the deposited layer to be patterned on a base layer without using a rennost layer. By changing the etching speed of the irradiated area,
Since this method uses the difference in etching speed before and after irradiation to remove the deposited layer by etching and form a pattern, it is possible to predict the amount of side etching more accurately than conventional methods, and it is also possible to Since it is not used, there is no dimensional conversion difference as in the conventional case, and therefore there is an advantage that pattern formation can be performed accurately. Furthermore, since no resist layer is used, the step of completely cleaning the resist layer can be omitted, which has the advantage of simplifying the manufacturing process and lowering the manufacturing cost.

(Description of Modifications) It is clear that the invention is not limited only to the embodiments described above, but that many modifications and variations can be made.

For example, in the above-mentioned embodiments, the patterning of a gutsivation film as a deposited layer and an insulating layer for stabilizing the characteristics of a semiconductor was explained, but the present invention is not limited to this, and is generally applicable to the manufacturing of semiconductor devices. It can also be applied to layers (or films) to be patterned, such as semiconductor layers, semi-insulating layers or metal layers. Therefore, in addition to the above-mentioned phosphorus and silicate glass, a layer of any material or substance can be used as the deposited layer.

Furthermore, although a semiconductor layer is used as the base layer, it is also possible to use a metal thin film, an insulating film, or other necessary layers or supports commonly used in the manufacture of semiconductor devices.

It will be appreciated that the deposition of the deposited layers described above can be carried out by deposition, growth, oxidative bonding, or any other method commonly used in the raw conductor technology.

The present invention is suitable for application to not only a single semiconductor device but also an integrated semiconductor device.

[Brief explanation of drawings]

1A to 1C are process diagrams for explaining a conventional pattern forming method for a semiconductor device, and FIGS. 2A to 2C are process diagrams for explaining a semiconductor device pattern forming method according to the present invention at each manufacturing stage. It is a process diagram showing the state of the device in an enlarged manner. 1. Base layer, 12. Sedimentary layer, 13. Radiation,
14 A portion of the deposited layer that has been irradiated with radiation, 15... A portion of the deposited layer that has not been irradiated with radiation. Patent applicant Oki Electric Industry Co., Ltd. Figure 1

Claims (1)

[Claims] forming a deposited layer to be patterned on the substrate surface;
The deposited layer is selectively irradiated with radiation, and the deposited layer is etched using the difference in etching rate between the portions of the deposited layer that are irradiated with the radiation and the portions that are not. A method for forming a pattern of a semiconductor device, characterized by molding.