KR19990011028A - Contact of semiconductor device and manufacturing method thereof - Google Patents

Abstract

An improved contact of a semiconductor device and a method of manufacturing the same are disclosed. A photosensitive material is formed on the upper surface of the semiconductor substrate on which the active region and the device isolation region are formed, and a photo development process is performed to form a self-aligned contact. Since the contacts are manufactured by self-alignment, a misalignment margin is secured, and thus a contact having a fine size suitable for a highly integrated semiconductor device can be manufactured. In addition, since the conventional complex process step is simplified to a single photo developing process, there is an advantage of reducing process time and cost.

Description

Contact of semiconductor device and manufacturing method thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the manufacture of semiconductor devices and, more particularly, to a method of manufacturing a semiconductor device having self-aligned contacts.

In general, as semiconductor devices become more integrated and faster, formation of fine patterns is required, and not only the width of the wiring but also the space between the wirings tends to decrease significantly. In particular, the sizes of the contacts connecting the isolated active element regions formed in the semiconductor substrate to the highly conductive thin film are formed while securing an alignment margin or the like, thus occupying a considerable area in the semiconductor device.

As the ultra-high density semiconductor device is rapidly developed in recent years, as the area of a unit cell is gradually reduced in the case of a memory device, an area in which a contact can be manufactured in a cell is also gradually reduced. Various methods have been studied to fabricate a contact of a fine size corresponding to the area of a unit cell which is gradually reduced. For example, there is a method of forming a small contact pattern on the photoresist film, but the development is slowed due to the limitation of the resolution technology. In order to solve such a problem, methods of forming a large contact pattern in photolithography and then adding various processes have been studied. For example, the method may be further described. A photoresist film is formed on a commonly used insulating film, such as BPSG (hereinafter referred to as BPSG), a large contact hole is formed according to a mask pattern, and the photoresist film is removed. After that, the nitride film was deposited and anisotropically etched to form the nitride film spacer, and then a fine contact could be formed. Another method is to form a photoresist film on an insulating film such as BPSG, form a large contact hole according to a mask pattern, and then flow the molten photoresist film at a predetermined temperature, for example, about 300 ° C. to form a patterned contact hole. The size was reduced and anisotropic etching was performed using this as a mask to form fine contacts.

However, in the case of manufacturing the contact according to the conventional method described above, the formation process or flow process of the nitride film spacer is added, the process step is complicated, it takes a long time, easy to generate particles, to remove the generated particles (particle) Since the anisotropic etching process, which must be accompanied by a cleaning process, must be performed, there is a problem that the manufacturing process of the contact hole is somewhat complicated. First of all, when manufacturing a contact according to the conventional method, there is a problem in that a process margin must be secured because self-aligned contact holes are not obtained. Further, in order to form the contact holes, a large contact hole is first formed in the photoresist film. In this process, since the contact hole is formed with a margin, it is difficult to form the contact of the highly integrated semiconductor device.

It is therefore an object of the present invention to provide a method for manufacturing a semiconductor device which can solve the above-mentioned conventional problems.

It is still another object of the present invention to provide a method for manufacturing a semiconductor device that can simplify a complicated contact manufacturing process and reduce process time and cost.

Another object of the present invention is to provide a method for manufacturing a semiconductor device that can solve the problem of particles generated in a complex contact manufacturing process.

Still another object of the present invention is to provide a method for manufacturing a semiconductor device which can improve integration by securing a fine alignment margin by forming a fine contact using a highly accurate self-aligning method.

1A to 1D are cross-sectional views shown for explaining the method for manufacturing a semiconductor device according to the present invention.

In order to achieve the above objects, in the present invention,

Forming an isolation layer on the semiconductor substrate, and forming an insulating film to function as a spacer on the upper side and both sidewalls of the gate made of the insulating film and the polysilicon; Forming a photosensitive material which functions as an interlayer insulating film and completely covers the insulating film formed on the semiconductor substrate and the gate; Positioning a contact hole on the photosensitive material and applying a mask to perform a photo development process; Forming self-aligned contact holes by insulating films formed on the upper sidewalls and both sidewalls of the gate; And filling a conductive material into the self-aligned contact hole to form a self-aligned contact.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in more detail. It should be noted that the same elements in the figures are denoted by the same numerals wherever possible. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

1A through 1E are cross-sectional views sequentially illustrating a method of manufacturing a semiconductor device having a self-aligned contact according to the present invention.

Referring to FIG. 1A, a semiconductor substrate 10 in which a device isolation layer 20, a gate region made of a gate insulating layer 30, and a polysilicon 40 is sequentially formed is shown. An insulating film 50 to function as a spacer is formed on the top and sidewalls of the gate region. A photosensitive material 60 is then formed on the front surface of the semiconductor substrate on which the gate region is formed to function as an interlayer insulating film. Formation of the photosensitive material 60 is the most important process in the embodiment of the present invention. This is because the position of the contact hole is self-aligned by the insulating film formed on the upper side and the sidewall of the gate, and by forming a photosensitive material on the position of the self-aligned contact hole, an accurate contact hole can be obtained even with a rough mask. Preferably, the photosensitive material 60 is a low viscosity containing a solvent (solvent) and the like. Then, the entire photosensitive material 60 is anisotropically etched. In this case, the photosensitive material 60 is etched to have a certain thickness in consideration of shrinkage in a subsequent thermal process.

Referring to FIG. 1B, after the mask 70 is disposed on the etched photosensitive material 60, a photodevelopment process is performed to partially expose a position where a contact hole is to be formed. In this case, even when the mask 70 is rough, the spacer 50 formed on the sidewall of the gate region serves as a precise mask, so that the mask 70 may be developed by exposing an accurate position.

Referring to FIG. 1C, a fine contact hole self-aligned to the semiconductor substrate 10 is formed at a position a by the photolithography process. The contact hole a diameter may be smaller than the distance between the two gate regions due to the insulating film 50 that is similar to or interposed between the two gate regions. Since the insulating film 50 formed on the upper side and both sidewalls of the gate is not removed by exposure in the photolithography process, the contact hole a is formed by the insulating film 50, thereby forming a self-aligned fine size according to the present invention. The contact can be made.

Referring to FIG. 1D, after baking the photosensitive material having a fine contact hole a by heat processing, the photosensitive material which is thermosetting is sufficiently cured so that no further shrinkage occurs in a subsequent thermal process. do. Then, a conductive material is filled in the contact hole to form a self-aligned contact and wire the electrode.

As described above, the present invention uses a photosensitive material instead of an interlayer insulating film such as BPSG used in the conventional contact forming method, so that the contact hole can be formed at a fine and accurate position self-aligned by the insulating film spacer in one photo process. It became. As a result, the process margin can be reduced by self-aligning without having a masking margin, thereby improving the integration of semiconductor devices.

In addition, the anisotropic etching process, which takes a long time and the cleaning process is inevitable due to the generation of particles, is omitted, thereby simplifying the process step, thereby reducing process time and cost.

As described above, although described with reference to a preferred embodiment of the present invention, it will be understood that various modifications and changes can be made without departing from the spirit and scope of the invention as set forth in the claims below. .

Claims (12)

In the contact manufacturing method of a semiconductor device: Forming a device isolation film on the semiconductor substrate, sequentially forming a gate made of an insulating film and polysilicon, and an insulating film functioning as a spacer on the upper side and both sidewalls of the gate; Forming a photosensitive material which functions as an interlayer insulating film and completely covers the semiconductor substrate and the insulating film; Forming a contact hole by a self-aligning method by performing a photolithography process on the formed photosensitive material; Baking and curing the photosensitive material having the self-aligned contact hole formed at a predetermined temperature; Filling the conductive material into the self-aligned contact hole to form a self-aligned contact, and then forming an electrode wiring. The method of claim 1, wherein the photosensitive material having the contact hole formed is baked at about 300 ° C. to cure. The method of claim 1, wherein the self-aligned contact is formed by a spacer insulating layer formed on the gate line and the sidewalls. The method of claim 1, wherein a conductive material such as polysilicon is filled in the contact hole to form the self-aligned contact. The method of claim 1, wherein the photosensitive material comprises a volatile material such as solvent. The method of claim 1, wherein the mask used in the photolithography process is generally rough. Semiconductor device: A semiconductor substrate in which a device isolation film, a gate made of an insulating film and polysilicon, and an insulating film serving as spacers are formed on top and both sidewalls of the gate; A photosensitive material which functions as an interlayer insulating film and completely covers the semiconductor substrate and the insulating film; The photosensitive material having contact holes self-aligned through a photolithography process; The photosensitive material including the self-aligned contact hole and baked and cured at a predetermined temperature; And a conductive wiring filling the conductive material into the self-aligned contact hole, and an electrode wiring on the semiconductor substrate having the self-aligned contact. The semiconductor device of claim 7, wherein the photosensitive material having the contact hole is baked at about 300 ° C. 9. 8. The semiconductor device of claim 7, wherein the self-aligned contact is formed by a spacer insulating film formed on the gate line and the sidewalls. 8. The semiconductor device of claim 7, wherein the self-aligned contact is formed by filling an inside of the self-aligned contact hole with a conductive material such as polycrystalline silicon. 8. The semiconductor device according to claim 7, wherein the photosensitive material comprises a volatile material such as a solvent. 8. The semiconductor device according to claim 7, wherein the mask used in the photolithography process is generally rough.