KR20010060565A - Method of manufacturing a capacitor in a semiconductor device - Google Patents

Abstract

PURPOSE: A method for manufacturing a capacitor of a semiconductor device is provided to guarantee sufficient capacitance and an excellent leakage current characteristic while performing a high temperature thermal process, by using cobalt silicide to form an adhesion layer in a lower portion of a contact hole, and by using cobalt silicide and Ir/Ruby to form a contact plug and a lower electrode. CONSTITUTION: After an insulating layer(12) and a nitride layer(13) are sequentially formed on a substrate(11) having a lower structure, a selected portion of the nitride layer and the insulating layer is etched to form a contact hole(14). An adhesion layer(15) is formed on the exposed substrate in a lower portion of the contact hole by using cobalt silicide. A contact plug and a material to be used as a lower electrode(16) are deposited on the entire structure including the contact hole having the adhesion layer. A selected region of the lower electrode material layer is etched to complete the lower electrode. A dielectric layer(17) and an upper electrode(18) are sequentially formed on the entire structure having the lower electrode.

Description

Method of manufacturing a capacitor in a semiconductor device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a capacitor of a semiconductor device, and more particularly, to a method of manufacturing a capacitor of a semiconductor device to improve the operation speed of a device and to simplify a process.

In general, dopant polysilicon is used as a contact plug for vertical wiring of a silicon substrate and a lower electrode in a DRAM BST capacitor, an FeRAM SBT, and a PZT capacitor. However, the resistivity of doped polysilicon is limited to increasing the speed of the device to thousands of microns. In addition, in order to fill the doped polysilicon into the contact hole in the form of a plug, a process of depositing or polishing the surface by chemical vapor deposition is required, and then platinum (Pt) and iridium (Ir), which are lower electrodes of the high-k dielectric film, are deposited. ) To form an adhesive layer using titanium silicide or the like for ohmic contact with a metal such as ruthenium (Ru), and then use a nitride such as titanium nitride to suppress the reaction between the lower electrode and the silicide. Therefore, there is a problem in that a complicated process such as forming a diffusion barrier film must be performed.

Therefore, the present invention forms cobalt silicide (CoSi _x ) at the bottom of the capacitor plug contact hole and uses it as an adhesive layer, and by using irrium (Ir) which is not reactive with cobalt silicide as the capacitor plug and processing it as a lower electrode, It is an object of the present invention to provide a method for manufacturing a capacitor of a semiconductor device capable of simplifying the process and stably performing a high temperature thermal process.

In the method of manufacturing a capacitor of a semiconductor device according to the present invention for achieving the above object, the insulating film and the nitride film are sequentially formed on a substrate on which a lower structure is formed, and then the contact holes are formed by etching selected portions of the nitride film and the insulating film. step; Forming a contact layer using cobalt silicide on the exposed substrate at the bottom of the contact hole; Depositing a material to be used as a contact plug and a lower electrode on the entire structure including the contact hole in which the contact layer is formed; Etching the selected region of the lower electrode material layer to complete the lower electrode; And sequentially forming a dielectric film and an upper electrode on the entire structure in which the lower electrode is formed.

1A to 1D are cross-sectional views of devices sequentially shown to explain a method of manufacturing a capacitor of a semiconductor device according to the present invention.

<Description of the symbols for the main parts of the drawings>

11 substrate 12 insulating film

13 nitride film 14 contact hole

15 contact layer 16 lower electrode

17 dielectric film 18 upper electrode

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

1A to 1D are cross-sectional views of devices sequentially shown to explain a method of manufacturing a capacitor of a semiconductor device according to the present invention.

Referring to FIG. 1A, after forming the insulating film 12, the insulating film 12, and the nitride film 13 having a high etching selectivity using an oxide on the substrate 11 on which the lower structure is formed, the substrate 11 and The contact hole 14 is formed by etching the selected portion of the nitride film 13 and the insulating film 12 for the vertical wiring between the capacitors. Thereafter, cobalt silicide (CoSi _x ) is deposited as a contact layer 15 for ohmic contact on the exposed substrate 11 at the bottom of the contact hole 14.

Referring to FIG. 1B, a contact plug and a lower electrode material layer are formed by using iridium (Ir) or ruthenium (Ru) on an entire structure including a contact hole 14 having a contact layer 15 formed at a bottom thereof. . Here, the lower electrode material is formed by depositing iridium (Ir) or ruthenium (Ru) to a thickness of 3000 to 10000 kPa by chemical vapor deposition.

Referring to FIG. 1C, the selected region of the iridium (Ir) film is removed by a photolithography and an etching process using a mask to complete the lower electrode 16. Here, titanium nitride (TiN) or silicon oxide film (SiO ₂ ) is used as a hard mask for etching the lower electrode 16.

Referring to FIG. 1D, a heat treatment process is performed to form the dielectric film 17 on the entire structure in which the lower electrode 16 is formed and to crystallize the dielectric film 17. Thereafter, an upper electrode 18 is formed on the dielectric film 17 and a heat treatment process for stabilizing an interface with the dielectric film 17 is performed. Here, the dielectric film 17 is formed by depositing BST, which is a high dielectric thin film, at a thickness of 150 to 500 Å. After the dielectric film 17 is formed, the heat treatment step proceeds by rapid heat treatment for 5 to 300 seconds at a temperature of 450 to 800 ° C. in an oxygen and nitrogen or oxygen and argon gas atmosphere. In addition, the upper electrode 18 is formed by depositing platinum (Pt) or iridium (Ir) to a thickness of 500 to 2500Å by chemical vapor deposition. The heat treatment process after the formation of the upper electrode 18 is performed at a temperature of 450 to 800 ° C. in an oxygen and nitrogen or oxygen and argon mixed gas atmosphere.

Capacitors formed in this way have sufficient capacitance and excellent leakage current characteristics, and have fast operating speeds.

As described above, according to the present invention, a contact layer is formed on the bottom of the contact hole using cobalt silicide (CoSi _x ) without using polysilicon having a high resistivity, and a metal (Ir or Ru) which is not reactive with cobalt silicide is formed. By forming the contact plug and the lower electrode by using the step, the process can be simplified. In addition, while performing a high temperature thermal process, it is possible to secure sufficient capacitance and excellent leakage current characteristics, and improve the operation speed of the device.

Claims (7)

Sequentially forming an insulating film and a nitride film on the substrate on which the substructure is formed, and then forming a contact hole by etching selected portions of the nitride film and the insulating film; Forming a contact layer using cobalt silicide on the exposed substrate at the bottom of the contact hole; Depositing a material to be used as a contact plug and a lower electrode on the entire structure including the contact hole in which the contact layer is formed; Etching the selected region of the lower electrode material layer to complete the lower electrode; And And sequentially forming a dielectric film and an upper electrode on the entire structure in which the lower electrode is formed. The method of claim 1, The contact plug and the lower electrode material layer is formed by depositing iridium or ruthenium to a thickness of 3000 to 10000 Å by chemical vapor deposition. The method of claim 1, In the etching process of the lower electrode material layer capacitor manufacturing method of a semiconductor device, characterized in that using a titanium nitride or silicon oxide film as a hard mask. The method of claim 1, The dielectric film is a capacitor manufacturing method of the semiconductor device, characterized in that formed by depositing a BST to a thickness of 150 to 500Å. The method of claim 1, After the dielectric film is formed, the semiconductor device further comprises the step of performing a rapid heat treatment for 5 to 300 seconds at a temperature of 450 to 800 ℃ in oxygen and nitrogen or oxygen and argon gas atmosphere for crystallization of the dielectric film Capacitor manufacturing method. The method of claim 1, The upper electrode is a capacitor w manufacturing method of a semiconductor device, characterized in that formed by depositing a platinum or iridium to a thickness of 500 to 2500Å by chemical vapor deposition. The method of claim 1, And forming a heat treatment process at a temperature of 450 to 800 ° C. in a mixed gas atmosphere of oxygen and nitrogen or oxygen and argon to stabilize the interface between the upper electrode and the dielectric layer after forming the upper electrode. Capacitor manufacturing method.