JPH0738385B2 - Asssing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] In the ashing of a resist, the present invention first performs a normal ashing, and then, in the next chamber, heats a wafer by using a chlorine-based gas to remove a metal contained in the resist. Impurities can be removed.

[Industrial application field]

The present invention relates to a resist ashing device,
More specifically, it relates to an ashing device having two chambers, a resist ashing chamber and a metal removing cleaning chamber.

[Conventional technology]

Microfabrication in a semiconductor integrated circuit or the like is performed by etching an underlying insulating film, semiconductor film, or metal film through a resist film having a pattern formed by exposure or phenomenon. After the microfabrication, that is, the etching is completed, the resist film used for the mask needs to be removed from the wafer surface. In conventional wet processing using liquid chemicals, hot concentrated sulfuric acid, hydrogen peroxide, organic solvents, hot organic acids, etc. have been appropriately selected and used according to the base material.
However, these liquid chemicals used in the wet resist removing process cannot be said to be clean, and contain various impurities, which can be a cause of pattern defects and a source of contamination. This is a major obstacle in improving the level of fine processing. Also, the amount of chemicals used is large, and the work is completely manual and inefficient, which is not an economical method. further,
Many of the chemicals used in this process are harmful to the human body, and there are problems in terms of work safety and prevention of pollution to waste liquid treatment, and the treatment method using liquid chemicals needed to be revised.

So resist removal method of ashing the resist using an O ₂ plasma in recent years which was pioneered in the wafer processing technique using a gas plasma, the O ₂ plasma ashing evils and fixation of the wet processing It eliminates the technical problems of, and simplifies, cleans, and stabilizes the process, and also facilitates automation.

For example, the principle of ashing of a resist film by O ₂ plasma is as follows: the molecular oxygen of the polymer resin is lowered by a chemical reaction between atomic oxygen O generated in the O ₂ plasma and the polymer resin, and CO _{2 is} generated by the oxidation of the low molecular resin. and it is those with decomposition and vaporization action of the H ₂ O, and simply is one of the resist film referred to as C _x H _y based on _{C x H y + O → CO} 2 + H 2 O made reaction It is considered. Generally, such resist removal is called ashing (ashing), but it is actually equivalent to vaporizing the resist.

Since the plasma process is cleaner than the wet process, it contributes to the improvement of the yield and reliability of the integrated circuit having the fine pattern.

[Problems to be solved by the invention]

However, even if such a plasma ashing apparatus having an excellent ashing capability is used, there is a problem that metal impurities contained in the resist remain on the wafer.

With the size of a conventional wiring pattern, the residual metal impurities have little influence on the device characteristics, which is not a serious problem. However, it has been recognized that the residual metal impurities influence the characteristics as the pattern becomes finer due to the high integration in recent years.

As described above, metal impurities, which have not been a serious problem in the conventional wiring pattern, have a problem that the characteristics of the device are deteriorated with the miniaturization of the pattern due to the recent integration.

The present invention has been made in view of the above circumstances, and provides an ashing device in which metal (metal impurities) 13 contained in a resist does not remain when the resist on the wafer 11 is removed. With the goal.

[Means for solving problems]

In order to achieve the above object, the ashing device of the present invention is
As shown in FIG. 1, an ashing chamber 12 for ashing the resist of the wafer 11 and a cleaning chamber 14 for removing the metal 13 of the wafer 11 are provided. Reactive chlorine gas 16,
A mechanism for introducing and discharging the gas into the chamber 15 and a wafer heating heater 17 are provided.

[Action]

Thus, in addition to the resist ashing chamber 12, the ashing device of the present invention includes a cleaning chamber 14 for removing the metal 13.
By providing the metal impurities remaining on the wafer 11
Since 13 can be removed, it is possible to prevent deterioration of device characteristics due to metal impurities.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.
This embodiment shows an example of the present invention, and the present invention is not limited to this.

FIG. 1 shows an overall configuration diagram of an embodiment of the present invention.

As shown in FIG. 1, the ashing apparatus of this embodiment includes an ashing chamber 12 for ashing a resist on a wafer 11,
There are two chambers 15 of a cleaning chamber 14 for removing the metal 13 of the wafer 11, and the cleaning chamber 14 has:
A chlorine-based gas 16 that reacts with a metal, a mechanism for inserting and discharging the gas into the chamber 15, and a heater 17 for heating a wafer are provided.

The ashing chamber 12 is equipped with a generally used resist ashing apparatus, and various apparatuses are conceivable. Among them, a plasma ashing apparatus having high ashing capacity and clean can be preferably used.

The cleaning chamber 14 for removing the metal 13 of the wafer 11 is equipped with a device for removing the metal impurities 13 contained in the resist.

The cleaning chamber 14 and the ashing chamber 12 are separated by independent chambers (airtight chambers) 15.

The metal removing device in the cleaning chamber 14 includes a chlorine-based gas 16 that reacts with a metal, a mechanism for introducing and discharging the gas into the chamber 15, and a heater 17 for heating a wafer, and residual metal impurities 13 contained in the resist 13 (Eg Fe, Cr, Cu
Etc.) and chlorine-based gas 16 are reacted to remove as chloride.

Although various gases can be used as the chlorine-based gas 16 that reacts with the metal, Cl ₂ and HCl are preferably used in this embodiment.

The gas 16 is introduced into and discharged from the chamber 15 using an air pump or the like.

A heating lamp was used as the wafer heating heater 17.

Next, the processing operation when the ashing device of this embodiment is used will be described.

As shown in FIG. 1, in this embodiment, since different treatments are performed for each chamber 15 that maintains airtightness, the treatment gas and dust in the previous chamber are not brought into the next chamber, so During load lock (Load
-Lock) 18 is provided.

The wafer 11 transferred from the load lock 18 is first subjected to normal ashing in the ashing chamber 12 to remove the resist. The wafer 11 is again sent to the cleaning chamber 14 of the next chamber through the load lock 18.

In this embodiment, the chlorine-based gas 16 that reacts with the metal is (O ₂ + Cl
₂ ) is used to fill the chamber 15 with a gas introduction mechanism. Then, when the wafer heating heater 17 is adjusted to 300 to 400 ° C. to heat the wafer 11 to a high temperature, the metal impurities 13 remaining on the wafer 11 and the chlorine-based gas 16 react to form chloride. Further, the chlorine-based gas 16 is discharged to the outside of the chamber 15 by the gas discharge mechanism.

By the above processing, the resist on the wafer 11 is a metal impurity.
Since it is completely removed including 13 as well, deterioration of device characteristics due to metal contamination can be prevented.

〔The invention's effect〕

As described above, by using the ashing device of the present invention, the resist can be removed and the metal impurities in the resist that tend to remain can be removed, so that the characteristic deterioration due to metal contamination can be prevented.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention. In FIG. 1, 11 is a wafer, 12 is an ashing chamber, 13 is a metal (metal impurity), 14 is a cleaning chamber, 15 is a chamber, 16 is a chlorine-based gas, 17 is a heater for heating a wafer, and 18 is a heater.
Is a load lock.

Claims (1)

[Claims] 1. A ashing chamber (12) for ashing a resist of a wafer (11), and a cleaning chamber (14) for removing a metal (13) of a wafer (11). The cleaning chamber (14) includes a chlorine-based gas (16) that reacts with a metal, a mechanism for introducing and discharging the gas into the chamber (15), and a wafer heating heater (17). Ashing device.