Influence of artificial metallic defects size on the surface cleaning process

2006 ◽  
Author(s):  
J. Capoulade ◽  
J. Y. Natoli ◽  
S. Palmier ◽  
J. L. Rullier ◽  
I. Tovena
Keyword(s):  
Surface Cleaning ◽  
Cleaning Process

CO2 SPRAY CLEANING AND OSEE NON-CONTACT INSPECTION FOR WIRE BOND PAD PREPARATION

2014 ◽  
Vol 2014 (1) ◽  
pp. 000307-000312
Author(s):  
David Jackson
Keyword(s):  
Surface Treatment ◽  
Treatment Process ◽  
High Reliability ◽  
Ambient Air ◽  
Surface Cleaning ◽  
Wire Bonding ◽  
Cleaning Process ◽  
Plasma Surface Treatment ◽  
Wide Range ◽  
Bond Pads

Surface pad contamination is a major cause of poor performance for wire bonding operations. Examples of the wide range of contaminants that can degrade wire bond pull strength include, for example:Halogens and hydrocarbons: plasma etching, epoxy outgassing (dry processing), photoresist strippers, cleaning solvents.Contaminants from plating operations: thallium, brighteners, lead, iron, chromium, copper, nickel, hydrogen.Sulfur compounds: packing containers, ambient air, cardboard and paper, rubber bands.Miscellaneous organic contaminants: epoxy outgassing, photoresist, general ambient air (poor storage).Miscellaneous inorganic compounds: sodium, chromium, phosphorous, bismuth, cadmium, moisture, glass, vapor, nitride, carbon, silver, copper, tin.Human sources of contamination: skin particles, hair, sweat, spittle, mucus, cosmetics, hand lotions, facial make-up and fibers from clothing. As can be seen, there are many types of surface contaminations that may challenge a wire bonding operation, all of which must be removed to insure reliable and strong bonds. In this regard, conventional precision cleaning processes for high reliability surface pad preparation typically involve multiple steps, chemistries, and equipment to accomplish complete decontamination. Moreover, conventional cleaning methods are sometimes non-selective for the surface contaminants and substrates. For example, conventional vacuum plasma using Ar/O2 is typically used to clean bond pads. Vacuum plasmas are usually performed off-line, taking up to 30 minutes to complete, and are non-selective for the organic contamination. The entire organic substrate (i.e., PCB) is etched away during the plasma cleaning process to remove the bond pad contamination. During treatment, secondary organic surface contaminations (plasma treatment by-products from reacted substrate) are produced which can re-contaminate bonding surfaces. Advanced carbon dioxide (CO2) spray cleaning technology provides various methods for consistently preparing bond pads for critical wire bonding operations. A patented hybrid CO2 particle-plasma spray is presented in this paper that has demonstrated efficacy for selectively treating bond pad surfaces to remove a wide range of challenging surface contaminations. Moreover, a novel non-contact surface inspection technology called Optically Stimulated Electron Emission (OSEE) - developed to address surface cleaning and inspection issues that led to the 1986 Challenger Spacecraft explosion - is used to measure the effectiveness of the new CO2 surface cleaning processes. Statistically significant studies have been performed to determine the effectiveness of the selective CO2 particle-plasma surface treatment process for preparing bond pads for gold ribbon bonding operations. One such study compared and contrasted the performance of this new single-step CO2 surface treatment method with that of a conventional multi-step solvent-plasma method. The two treatment methods were used to prepare the surface of a metalized ceramic wafer that simulated bond pad surfaces and treatment areas representative of an actual high-reliability electronic board. The test results of this evaluation demonstrated that the CO2 particle-plasma surface treatment process is statistically similar to or sometimes better than a solvent-plasma hybrid cleaning process. CO2 spray cleaning was determined to be better for some types of contaminants as well – and in particular more relevant mixed-contaminant challenge tests. The CO2 cleaning process demonstrates a lower defect-per-million (DPM) level and an improved CpK. Finally, in this study OSEE surface quality analysis was performed before and after surface cleaning. OSEE analysis provided a reliable non-contact means of determining the proper level of surface pad preparation.

Si Surface Preparation: The Effect of Small Amounts of Carbon Contamination and Sputter Induced Surface Roughness

1992 ◽  
Vol 259 ◽  
Author(s):  
Iain D. Baikie
Keyword(s):  
Work Function ◽  
Elevated Temperatures ◽  
Surface Preparation ◽  
Surface Cleaning ◽  
Residual Carbon ◽  
Cleaning Process ◽  
Kelvin Probe ◽  
Carbon Contamination ◽  
Oxygen Penetration ◽  
Cleaning Methods

ABSTRACTThe sputter-anneal cleaning process is one of the most common methods of producing clean, defect free, crystalline Si surfaces. However the effects of small amounts of residual Carbon, probably the most insidious surface contaminant, and of Inhomogeneities in the sputter profile have not been investigated in any detail.Using a very high resolution Kelvin probe coupled with Auger Electron Spectroscopy (AES), we have followed the changes in work function, together with surface contaminants, throughout the cleaning process. We show that very small amounts of surface carbon contamination, at or about the AES detection limit, lead to a significant increase in work function of the “Clean surface”. Further as little as 0.6% Carbon substantially influences the initial stages of oxidation of the Si(111) 7×7 surface by (i) hindering formation of the elementary dipole layer and (ii) enhancing oxygen penetration through the surface layer into deeper layers.We have also measured work function profiles of a Si(111) 7×7 sample during sputtering. Inhomogeneities in the sputter profile, particularly around the periphery, are clearly evident and produce variations in work function of some 200 meV across the specimen. Repeated sputter-anneal cycles lead to a degree of disorder in these regions and this is reflected in a different oxidation behaviour.We conclude that work function measurements are both simple to perform and can be utillsed to determine the presence of surface contamination and roughness. As the oxide layer thickness in MOS devices continues to diminish the detection and elimination of residual Carbon contamination will play an ever increasing role in determining device performance. The Kelvin probe can be used at elevated temperatures and pressures and has potential applications in alternative surface cleaning methods including flash annealing and chemical preparations.

Study on Aluminum Frame Surface Cleaning Process for Photomask Pellicle Fabrication

2015 ◽  
Vol 25 (9) ◽  
pp. 462-467
Author(s):  
Hyun-Tae Kim ◽  
◽  
Hyang-Ran Kim ◽  
Min-Su Kim ◽  
Jun Lee ◽  
...  
Keyword(s):  
Surface Cleaning ◽  
Cleaning Process

Post CMP Cleaning Using Ice Scrubber Cleaning

1995 ◽  
Vol 386 ◽  
Author(s):  
N. Takenaka ◽  
Y. Satoh ◽  
A. Ishihama ◽  
K. Sakiyama
Keyword(s):  
Mass Spectroscopy ◽  
Chemical Mechanical Polishing ◽  
High Speed ◽  
Surface Cleaning ◽  
Wafer Surface ◽  
Cleaning Process ◽  
Mos Capacitors ◽  
Metal Impurities ◽  
Cleaning Technology ◽  
Si Wafer

ABSTRACTThe surface cleaning technology with the use of ice scrubber cleaning has been developed to remove the particles after Chemical Mechanical Polishing (CMP) process. The ice particles with a high speed nearly equal to the sound velocity bombarded the Si wafer surface, as a result, the residue from the slurry solution was reduced from ∼5/cm2 to ∼0.05/cm2 and the metal impurities are completely eliminated below the defect limitation for ICP mass spectroscopy. The charge build-up damage due to the high speed particles is not introduced into the the MOS capacitors. This technology is quite effective, compared with the conventional brush scrubber method and is applicable for the cleaning process below the quarter micron devices.

Surface cleaning process for plasma-etched SiC wafer

2020 ◽  
Vol 126 (8) ◽  
Author(s):  
Lihuan Zhao ◽  
Haiping Shang ◽  
Dahai Wang ◽  
Yang Liu ◽  
Miao Xue ◽  
...  
Keyword(s):  
Surface Cleaning ◽  
Cleaning Process ◽  
Sic Wafer
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