System for wafer cleaning

• US 6,235,145 B1
• Filed: 07/20/1998
• Issued: 05/22/2001
• Est. Priority Date: 11/13/1995
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Torek, Kevin, Li, Li, Westmoreland, Donald L., Hawthorne, Richard C.
• Primary Examiner(s): Kunemund, Robert
• Assistant Examiner(s): UMEZ ERONINI, LYNETTE T
• Application Number:
  US09/119,160
• Time in Patent Office: 1,037 Days
• Field of Search: 134/1.2, 134/902, 156/345, 438/706
• US Class Current: 156/345.29
• CPC Class Codes: C09K 13/06 with organic material
• CPC Class Codes: H01L 21/02049 with gaseous HF
• CPC Class Codes: H01L 21/02063 the processing being the formation of vias or contact holes
• CPC Class Codes: H01L 21/02068 during, before or after processing of conductive layers, e.g. polysilicon or amorphous silicon layers
• CPC Class Codes: H01L 28/84 being a rough surface, e.g. using hemispherical grains
• CPC Class Codes: Y10S 438/906 Cleaning of wafer as interim step

Abstract

A method of cleaning wafer surfaces includes providing a wafer surface and cleaning the wafer surface using at least hydrofluoric acid (HF) and an etch reducing component. The etch reducing component is from the group of (R)₄NOH wherein R═(C₁-C₂₀)alkyls, either straight or branch chained, and further wherein each R is independently a (C₁-C₂₀)alkyl, preferably a (C₁-C₄)alkyl, and more preferably one of tetra ethyl ammonium hydroxide (TEAH) and tetra methyl ammonium hydroxide (TMAH). A cleaning solution for use in cleaning a wafer surface includes an H₂O diluted HF solution and an etch reducing component from the group above, preferably, TMAH. A system for performing an HF vapor cleaning process includes a vapor chamber for positioning a wafer having a wafer surface and means for providing an HF vapor to the vapor chamber. The HF vapor includes an inert carrier gas, an HF component, one of a water vapor or an alcohol vapor, and an etch reducing component. The etch reducing component may be from the group above, preferably, TMAH.

Claims

1. A system for performing an HF vapor cleaning process, comprising:

a single vapor chamber for positioning a wafer having a wafer surface;

a carrier gas source for providing an inert carrier gas;

a vapor source operable using the inert carrier gas for providing one of a water vapor or an alcohol vapor to the single vapor chamber;

a hydrofluoric acid (HF) source for providing a hydrofluoric acid component to the single vapor chamber;

an etch reducing component source for providing an etch reducing component to the single vapor chamber; and

wherein the single vapor chamber provides an HF vapor for cleaning the wafer surface, the HF vapor including a combination of;

the hydrofluoric acid (HF) component;

the one of a water vapor or an alcohol vapor; and

the etch reducing component, wherein the etch reducing component is from the group of (R)₄NOH wherein R═

(C₁-C₂₀)alkyls, either straight or branch chained, and further wherein each R is independently a (C₁-C₂₀)alkyl.

2. The system according to claim 1, wherein R is a (C₁-C₄)alkyl.

3. The system according to claim 2, wherein the etch reducing component is one of tetra ethyl ammonium hydroxide (TEAH) and tetra methyl ammonium hydroxide (TMA).

4. The system according to claim 3, wherein the etch reducing component is TMAH.

5. The system according to claim 4, wherein the etch reducing component is TMAH in an amount greater than about 0.01 ppm of the HF vapor.

6. The system according to claim 5, wherein the TMAH is in an amount in the range of 1 ppm to 500 ppm.