Browse Prior Art Database

Method for a wet-clean chemistry/recipe for semiconductor manufacturing

IP.com Disclosure Number: IPCOM000022276D
Publication Date: 2004-Mar-03
Document File: 3 page(s) / 75K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for a wet-clean chemistry/recipe for semiconductor manufacturing. Benefits include improved functionality, improved performance, improved reliability, improved yield, improved ease of implementation, and improved cost effectiveness.

This text was extracted from a Microsoft Word document.
This is the abbreviated version, containing approximately 44% of the total text.

Method for a wet-clean chemistry/recipe for semiconductor manufacturing

Disclosed is a method for a wet-clean chemistry/recipe for semiconductor manufacturing. Benefits include improved functionality, improved performance, improved reliability, improved yield, improved ease of implementation, and improved cost effectiveness.

Background

As the size of semiconductor devices shrink, they are becoming more susceptible to smaller defects that are increasingly difficult to remove. Very small defects (<0.15 µm) are difficult to remove using conventional wet clean techniques such as RCA standard clean1 (SC1), RCA standard clean2 (SC2), and a deionized (DI) water rinse during semiconductor processing. These defects can be polysilicon particulates that result from etch or planar processes. Alternatively, the defects may be Si-containing residue produced by other processing steps, such as lithography or dry etch. These defects have been found to degrade yield and reliability. For example, they can block etching, cause electrical shorts, or cause cycling breakdown between contact and gate structures.

Conventionally, one of two solutions are used:

•         Addition of physical energies (such as megasonics, scrubbing, and spraying). The limitation of this technique is that as device dimensions shrink, smaller features are susceptible to damage when subjected to physical energies.

•         Employment of chemistries that etch the layer beneath the defect to facilitate its removal. The limitation of this technique is in applicability, especially when etching the underlayer cannot be tolerated or is impractical.

General description

The disclosed method is the addition of tetramethylammonium hydroxide (TMAH) to aqueous solution wet clean chemistries (such as SC1) to improve the removal of organic and inorganic defects.

The disclosed method covers the use of TMAH addition to wet clean chemistries to enhance defect-removal efficiency. The improvement is made through the modification of surface chemistry conditions, using surfactants or surfactant-like agents. These agents serve to change the zeta potential in the chemical solutions to increase the repelling forces between defects and wafer surfaces.

Advantages

         The disclosed method provides advantages, including:

•         Improved functionality due to providing an alternative to physical methods of defect removal, such as scrub or megasonics, which have higher risk of damage to small device structures

•         Improved functionality due to providing increased particle removal without etching the surrounding medium

•         Improved performance due improving the removal efficiencies of physical removal systems or etching chemistries techniques

•         Improved reliability due to reducing cycling failures on memory devices because electrical breakdown in or around defects

•         Improved yield due to reducing the occurrence of defects

•         Improved ease of implementation due to being compatible with many conventional process steps

•         Improved eas...