Site News  |   Monitor Keywords  |   Monitor Archive  |   Organizer  |   Account Info  |

Method for resist strip in presence of low k dielectric material and apparatus for performing the same

Method for resist strip in presence of low k dielectric material and apparatus for performing the same description/claims

This application is a divisional application of U.S. patent application Ser. No. 10/916,685, filed on Aug. 11, 2004, the disclosure of which is incorporated in its entirety herein by reference.

This application is related to U.S. patent application Ser. No. 10/232,635, filed on Aug. 30, 2002, and entitled “H2O Vapor as a Processing Gas for Crust, Resist, and Residue Removal for Post Ion Implant Resist Strip.” The disclosure of this related application is incorporated herein by reference.

1. Field of the Invention

The present invention relates to semiconductor fabrication.

2. Description of the Related Art

During semiconductor fabrication, integrated circuits are created on a semiconductor wafer (“wafer”) composed of a material such as silicon. To create the integrated circuits on the wafer, it is necessary to fabricate a large number (e.g., millions) of electronic devices such as resistors, diodes, capacitors, and transistors of various types. Fabrication of the electronic devices involves depositing, removing, and implanting materials at precise locations on the wafer. A process called photolithography is commonly used to facilitate deposition, removal, and implantation of materials at precise locations on the wafer.

In the photolithography process, a photoresist material is first deposited onto the wafer. The photoresist material is then exposed to light filtered by a reticle. The reticle is generally a glass plate that is patterned with exemplary feature geometries that block light from passing through the reticle. After passing through the reticle, the light contacts the surface of the photoresist material. The light changes the chemical composition of the exposed photoresist material. With a positive photoresist material, exposure to the light renders the exposed photoresist material insoluble in a developing solution. Conversely, with a negative photoresist material, exposure to the light renders the exposed photoresist material soluble in the developing solution. After the exposure to the light, the soluble portions of the photoresist material are removed, leaving a patterned photoresist layer.

The wafer is then processed to either remove, deposit, or implant materials in the wafer regions not covered by the patterned photoresist layer. After the wafer processing, the patterned photoresist layer is removed from the wafer in a process called photoresist stripping. It is important to completely remove the photoresist material during the photoresist stripping process because photoresist material remaining on the wafer surface may cause defects in the integrated circuits. Also, the photoresist stripping process should be performed carefully to avoid chemically modifying or physically damaging underlying materials present on the wafer.

In one embodiment, a method for removing photoresist material from a substrate is disclosed. The method includes providing a substrate having a photoresist material overlying a low k dielectric material, wherein a portion of the low k dielectric material is exposed. The method also includes disposing H2O vapor over the substrate. The method further includes transforming the H2O vapor into a reactive form, wherein the reactive form affects a removal of the photoresist material from the substrate without causing substantial removal of the low k dielectric material exposed to the reactive form.

In another embodiment, a method for operating a photoresist stripping chamber is disclosed. The method includes placing a wafer within an internal volume of the photoresist stripping chamber, wherein the wafer has a photoresist material overlying a low k dielectric material. A portion of the low k dielectric material is exposed to the internal volume of the photoresist stripping chamber. The method also includes supplying H2O vapor to the internal volume of the photoresist stripping chamber. The method further includes applying power to the H2O vapor to transform the H2O vapor into a plasma including plasma ions. Additionally, the method includes allowing the plasma ions to react with the photoresist material. Reaction of the plasma ions serve to remove the photoresist material from the wafer without adversely affecting the low k dielectric material exposed to the internal volume of the photoresist stripping chamber.

In another embodiment, a photoresist stripping chamber (“chamber”) is disclosed. The chamber includes an internal region configured to contain a plasma. A wafer support structure is disposed within the internal region. The wafer support structure is configured to hold a wafer in exposure to the plasma. The chamber also includes an H2O vapor supply inlet configured to supply H2O vapor to the internal region. A power supply is also provided for transforming the H2O vapor within the internal region into the plasma. The plasma includes ions capable of removing photoresist material from the wafer without adversely affecting a low k dielectric material present on the wafer and exposed to the plasma.

In another embodiment, a photoresist stripping chamber (“chamber”) is disclosed. The chamber includes an internal region configured to contain a plasma. The chamber also includes a wafer support structure disposed within the internal region. The wafer support structure is configured to hold a wafer in exposure to the plasma. The wafer support includes a number of cooling channels. A heat exchanger is disposed in fluid communication with the number of cooling channels of the wafer support structure. The heat exchanger is defined to maintain a temperature of the wafer support structure. The chamber also includes an H2O vapor supply inlet configured to supply H2O vapor to the internal region of the chamber. A power supply is provided for transforming the H2O vapor within the internal region into the plasma. The plasma is capable of removing photoresist material from the wafer without adversely affecting a low k dielectric material present on the wafer and exposed to the plasma.

Other aspects and advantages of the invention will become more apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the present invention.

• Provisional Patent
• Utility Patent

• What Is a Patent?
• What Is a Trademark or Servicemark?
• What Is a Copyright?
• Patent Laws