KR20070069515A - W polishing pad of chemical mechanical polishing - Google Patents

Abstract

A tungsten polishing pad of a CMP process is provided to perform stably the maintenance according to temperature by installing a temperature detecting sensor at a portion between a heating unit and a cooling unit. An automated temperature control device is installed at a polishing pad, so that the maintenance is properly controlled according to the temperature detected at the polishing pad. The automated temperature control device includes a heating part(110) on an upper pad(100) of the polishing pad, a cooling unit(210) on a lower pad(200) of the polishing pad, and a temperature detecting sensor(150) between the heating part and the cooling part.

Description

Tungsten polishing pad of chemical mechanical polishing process

1 is a perspective view schematically showing the configuration of a conventional chemical mechanical polishing apparatus,

2 is a structural diagram showing a tungsten polishing pad of the chemical mechanical polishing process according to the embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

100: upper pad 110: heating means

150: temperature sensor

200: bottom pad 210: cooling means

The present invention relates to tungsten chemical mechanical polishing process management, and more particularly, to a tungsten polishing pad of a chemical mechanical polishing process that can stably control the process according to temperature by installing a temperature sensor in the polishing pad.

The chemical mechanical polishing (CMP) process of semiconductor wafers has been introduced because semiconductor devices have a multi-layered wiring structure and require more stringent wide area flattening and tighter depth of focus, and the devices become more microscopic and wafers As it becomes larger, the demand for chemical mechanical polishing in semiconductor manufacturing will increase rapidly. The chemical mechanical polishing (CMP) process is a process technology developed by IBM and researched and developed by leading semiconductor manufacturing companies in the United States and introduced and developed by domestic semiconductor manufacturing companies.

The chemical mechanical polishing (CMP) process is a process in which mechanical processing by an abrasive existing between a pressed wafer and a polishing pad and chemical etching by a compound such as a slurry occur simultaneously. 1 is a perspective view schematically showing the configuration of a conventional chemical mechanical polishing apparatus.

First, the polishing pad 10 is attached to the upper surface of the polishing table 50 and a wafer (not shown) having an insulating film is mounted on the polishing head 20, and the wafer is in close contact with the polishing pad 10. As the furnace wafer and the polishing table 50 rotate in opposite directions, mechanical polishing is performed. In addition, a slurry is introduced between the wafer and the polishing pad 10 through a slurry supply unit 30 that is separately installed to react with the insulating film on the wafer surface, thereby chemically polishing.

In order to precisely planarize by the chemical mechanical polishing process, the surface roughness and overall elasticity of the polishing pad 10 in contact with the wafer must be properly maintained. For this purpose, the state of the polishing pad 10 is changed during the chemical mechanical polishing process. The task of keeping it constant at all times is called polishing pad conditioning, and the device that performs the task is called dresser 40. The dresser 40 is mounted on the rotary shaft 41 and the lower surface of the rotary shaft 41 and is composed of a diamond disk 42 in direct contact with the polishing pad 10 to perform polishing pad conditioning. Polishing pad conditioning while rotating the diamond disk 42 and the polishing pad 10 in close contact with each other by driving the diamond disk 42 mounted on the dresser 40 in a region different from the wafer rotation during the process. This is done.

The dresser 40 is cleaned by the dresser cleaning apparatus 1 after finishing polishing pad conditioning. The dresser cleaning apparatus 1 may use ultra-pure water (DI water) to clean the receiving cup 2 having an upper surface open to accommodate the dresser 40 and the dresser 40 accommodated in the receiving cup 2. It is composed of an injection spray (3) and an injection nozzle (4) which is installed to inject de ionized water and an ultrapure water supply unit (5) for supplying ultrapure water to the injection spray (3) and the injection nozzle (4).

Accordingly, ultrapure water is injected while the dresser 40 is inserted into the receiving cup 2 and the dresser 40 is rotated to remove foreign substances such as slurry coming into contact with the dresser 40 during polishing pad conditioning. Cleaning is done. Variables affecting the chemical mechanical polishing (CMP) process include the process conditions of the polishing equipment, the deposition process of the wafer thin film, the chemical properties of the slurry, the polishing pad 10, the pad conditioning, and the post CMP process. Cleaning) process and equipment, wafer defect (Surface defect) analysis method, environmental problems due to the use of slurry and polishing pad (10).

In the conventional WCMP process, process parameter values are determined by pressure applied to a semiconductor wafer, RPM of a pad, and supply of a slurry. However, since the tungsten film is a metal, the temperature applied to the semiconductor wafer also has a great effect on the polishing rate or flatness of the tungsten film, but there is a problem that a control system is not set.

The present invention has been invented to solve the above problems, the chemical mechanical polishing that can stably manage the process management according to the temperature by installing a temperature sensor between the heating means and the cooling means as a tungsten chemical mechanical polishing process control The purpose is to provide a tungsten polishing pad of the process.

In the present invention for achieving the above object, in the tungsten chemical mechanical polishing process management, the temperature control sensor 150 is an automatic thermostat installed between the upper heating means 110 and the cooling means 210 of the lower temperature It is characterized by the stable process control according to.

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

2 is a structural diagram showing a tungsten polishing pad of the chemical mechanical polishing process according to the embodiment of the present invention. In the chemical mechanical polishing process, a polishing pad is generally a pad plate installed to support a plurality of pads, a buffer pad adhered to an upper surface of the pad plate to buffer contact force acting on the wafer during wafer polishing, and a contact with the wafer surface. It consists of a polishing pad adhered to the upper side of the pad. When the polishing pad reaches the end of its life and needs to be replaced with a new polishing pad, the polishing pad and the cushioning pad are removed with an adhesive after removing the existing polishing pad and the cushioning pad and cleaning the pad plate.

By the way, the present invention by installing a thermostat on the tungsten polishing pad to make the process control according to the temperature stable. The automatic temperature control device is integrated between the heating means 110 and the cooling means 210 of the upper by the temperature sensor 150 is integrated.

The upper heating means 110 is stacked in three layers as the upper pad 100, and the cooling means 210 in the bottom is stacked in three layers as the lower pad 200. The temperature sensor 150 is placed between the bottom layer of the upper pad 100 and the top layer of the lower pad 200 and bonded with an adhesive.

In the tungsten polishing pad configuration of the present invention configured as described above, the temperature measuring sensor 150 is mounted on the tungsten polishing pad as shown in FIG. 1 and the heating means 110 of the heating system is maintained to maintain a constant temperature. And cooling means 21 of the cooling system.

Thus, the heating system is operated at a low temperature at the beginning of polishing, and the chemical mechanical polishing (CMP) process is performed while appropriately adjusting the pad temperature to prevent overheating at the intermediate stage of polishing.

As described above, the tungsten polishing pad of the present invention is a tungsten chemical mechanical polishing (CMP) process using chemical mechanical polishing (CMP) when forming a semiconductor device, and a pad equipped with a temperature control device during the tungsten chemical mechanical polishing (CMP) process is applied. That's how you do it.

Although the technical idea of the tungsten polishing pad of the chemical mechanical polishing process of the present invention has been described based on the exemplary drawings, this is illustrative of the best embodiments of the present invention and is not intended to limit the claims of the present invention. It will be apparent to those skilled in the art that various modifications and imitations can be made without departing from the scope of the technical idea of the present invention.

As described above, according to the present invention, a tungsten polishing pad of a chemical mechanical polishing process capable of stably managing process according to temperature by installing a temperature sensor between the heating means and the cooling means as a tungsten chemical mechanical polishing process control. Can provide.

Claims (3)

A polishing pad of a tungsten chemical mechanical polishing device comprising: a tungsten polishing pad of a chemical mechanical polishing process configured to control a process management according to a temperature detected by a polishing pad by installing a thermostat on the polishing pad. The method of claim 1, The thermostat is a tungsten polishing pad of the chemical mechanical polishing process, characterized in that the heating means is installed on the upper pad, the cooling means is installed on the lower pad, a temperature sensor is installed between the heating means and the cooling means. The method according to claim 1 or 2, The thermostat is a tungsten polishing pad of the chemical mechanical polishing process, characterized in that for controlling the heating means and the cooling means according to the temperature of the pad detected by the temperature sensor to automatically adjust to a predetermined temperature.

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