KR100190194B1 - Manufacturing method of semiconductor device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, wherein the end portion of the device isolation insulating film is protected from being exposed from the bottom of the contact hole during charge storage contact formation using selective epitaxy growth and polycrystalline polysilicon deposition. It is a method which can improve the characteristic and the contact junction package of a semiconductor element.

Description

Manufacturing method of semiconductor device

1A is a cross-sectional view of a semiconductor DRAM device in which an electron storage contact is formed in accordance with the prior art.

FIG. 1B is a detailed view of part A of FIG. 1A

2A and 2B are cross-sectional views of a process for manufacturing a charge storage contact hole according to a first embodiment of the present invention.

3A to 3C are cross-sectional views of a process for manufacturing a charge storage contact hole according to a second embodiment of the present invention.

4A and 4B are cross-sectional views of a manufacturing process of a charge storage contact hole according to a third exemplary embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

1 semiconductor substrate 2 device isolation insulating film

3: gate oxide film 4: gate

5: Spacer 6: Source / Drain

7 insulating film 8 charge storage contact hole

9 charge storage electrode 10 dielectric

11 capacitor capacitor 13 single crystal layer

14 photosensitive film

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and in particular, to protect the end of the device isolation insulating film from being exposed from the bottom of the contact hole during charge storage contact formation using selective epitaxy growth and polycrystalline polysilicon deposition process. The present invention relates to a semiconductor device manufacturing method capable of improving refresh characteristics and contact leakage of a semiconductor device.

As semiconductor devices are increasingly integrated, the refresh characteristics of the devices are one of important factors for determining product characteristics. The refresh characteristics are generally determined by the contact characteristics of the charge storage region.

1A is a diagram showing a cross-sectional view of a DRAM formed according to the prior art.

Referring to FIG. 1A, after the device isolation insulating film 2 is formed on the semiconductor substrate 1 according to a conventional general process, the insulating film 7 is formed on the entire structure, and then using a contact mask. The lower insulating film 7 is etched to form the contact hole 8, and then the charge storage electrode 9 is formed on the source / drain region 6 using the contact hole 8. have.

In this case, the dielectric film 10 is thinly coated on the charge storage electrode 9, and the capacitor prater 11 is formed to a predetermined thickness on the entire surface of the upper portion of the charge storage electrode 9.

FIG. 1B is a detailed view of the portion A of FIG. 1A and shows the state of the contact hole 8 formed at the end of the device isolation insulating film 2.

As the DRAM becomes more highly integrated, as shown in FIG. 1B, the charge storage contact 8 damages the end portion of the isolation layer.

In the end portion of the isolation layer 2, there are usually many crystal defects, and when the dry etching process that causes the crystal defects occurs at the end of the device isolation insulating film 2, it becomes electrically weak and causes a drastic reduction in the refresh characteristics of the DRAM. have.

Therefore, in order to solve the above problems, the present invention protects the end of the device isolation insulating film from dry etching for forming a charge storage contact by using conventional processes such as selective epitaxial growth and polycrystalline polysilicon deposition. And to provide a method for manufacturing a semiconductor device that can improve the contact junction of the semiconductor device.

Features of the present invention for achieving the above object is the step of forming a device isolation insulating film on the semiconductor substrate by a known technique, the step of growing a single crystal semiconductor film of a predetermined thickness only on the exposed semiconductor substrate, Forming an insulating film on the substrate; forming a contact hole by etching the lower insulating film using a contact mask; and forming a charge storage contact using the exposed large contact hole.

Another feature of the present invention for achieving the above object is the step of forming a device isolation insulating film on the semiconductor substrate by a known technique, the step of depositing a polycrystalline semiconductor layer on the entire structure, and the high temperature heat treatment of the polycrystalline semiconductor layer Single crystallization, removing the deposition layer on the device isolation layer by a CMP process, forming an insulating film on the entire structure, and forming a contact hole by etching the lower insulating film using a contact mask And forming a charge storage contact using the exposed contact hole.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

2a to 2b show a first embodiment of the present invention, and FIG. 2a shows a device isolation insulating film 2 formed over the semiconductor substrate 1 by a conventional device isolation method, and selective epitaxial growth. It is sectional drawing in the state in which the single crystal semiconductor film 12 of constant thickness was grown only on the semiconductor substrate 1 by the method.

2b shows a state in which the charge storage contact 8 is formed by the conventional DRAM manufacturing process in the above structure.

Compared with FIG. 1b, it can be seen that the end of the isolation layer 2 can be protected without being exposed to contact dry etching by selective epitaxy growth and single crystal growth.

3A to 3C are manufacturing process diagrams illustrating a second embodiment of the present invention. After the selective epitaxial growth method or the polycrystalline semiconductor layer is deposited on the semiconductor substrate 1, it is subjected to monocrystallization by high temperature heat treatment. A cross-sectional view showing a manufacturing process of removing a growth layer or a deposition layer on an element isolation region, that is, a region in which an element activation region is removed by chemical mechanical polishing (hereinafter referred to as CMP).

3A illustrates a device isolation insulating film 2 formed on a predetermined portion of the semiconductor substrate 1 by a conventional device isolation method, and a single crystal layer 13 deposited on the entire surface of the semiconductor substrate 1 by a selective epitaxial growth method. Or a single crystal film 13 having a crystal structure similar to that of the semiconductor substrate 1 by a high temperature heat treatment after the polycrystalline layer is deposited on the entire surface.

3B is a cross-sectional view of the deposition layer 13 in a state where only the single crystal layer 13 on the device isolation insulating film 2 is removed by the CMP process.

3C is a cross-sectional view of a state in which the charge storage contact 8 is formed by etching the insulating film 7 after the insulating film 7 is formed over the entire structure.

In FIG. 3C, it can be seen that the end portion of the isolation layer 2 is protected without being exposed to the dry etching of the contact 8 through the above process.

4A and 4B are manufacturing process diagrams showing a third embodiment of the present invention.

Referring to FIG. 4A, the single crystal layer 13 deposited on the entire surface of the semiconductor substrate 1 through the process shown in FIG. 3A is dry-etched using the photosensitive film 14 to form an upper portion of the isolation layer 2 It is sectional drawing of the state which removed the single crystal layer 13 of.

4B is a cross-sectional view of a state in which a charge storage contact 8 is formed by forming an insulating film 7 having a predetermined thickness on the entire structure and then etching the insulating film 7 using a contact mask.

Also in the above case, it can be seen that the end of the device isolation insulating film is protected without being exposed to the dry etching of the contact 8, similarly to the above-described second and third embodiments.

Therefore, by protecting the end portion of the device isolation insulating film 7 with a semiconductor single crystal, it is possible to prevent the electrical characteristics of the semiconductor device from deteriorating by contact dry etching.

As described above, the method of manufacturing a semiconductor device according to the present invention protects the end of the device isolation insulating film with a semiconductor single crystal, thereby reducing the electrical characteristics of the contact formed portion when the contact is formed at the end of the device isolation film. I can solve it.

Claims (5)

Forming a device isolation insulating film on the semiconductor substrate by a known technique, growing a single crystal semiconductor film having a predetermined thickness only on the exposed semiconductor substrate, forming an insulating film on the entire structure, and forming a contact mask. Forming a contact hole by etching the lower insulating film using the exposed insulating film; and forming a charge storage contact using the exposed contact hole. The growth of the single crystal semiconductor film is a method for manufacturing a semiconductor device, characterized in that using the selective epitaxy growth method. Forming a device isolation insulating film on a semiconductor substrate by a known technique, depositing a polycrystalline semiconductor layer on the entire structure, single crystallizing the polycrystalline semiconductor layer by high temperature heat treatment, and performing the device isolation film by a CMP process. Removing an upper deposition layer, forming an insulating film over the entire structure, etching a lower insulating film using a contact mask to form a contact hole, and using the exposed contact hole to charge storage contacts Method of manufacturing a semiconductor device comprising the step of forming a. The method of claim 3, wherein a single crystal is grown on the entire exposed semiconductor surface by selective epitaxy growth instead of depositing a polycrystalline semiconductor layer on the entire upper surface of the semiconductor substrate. The method of claim 3, wherein the single crystal deposited on the entire upper surface of the semiconductor substrate is removed by dry etching using only a photosensitive film pattern.