Authors: Seung Jun Oh, Si Nae Song, Jong Yeong Jeon, Sun Young Lee, Taesung Kim
Abstract: Isopropyl alcohol (IPA) was used in the drying process to remove the contamination after the wet cleaning process. Regardless of the types of chemical solutions, the IPA is more strictly controlled because it is used. However, when the IPA was exposed to low acid concentration, the IPA polymers were generated to the di-isopropyl ether, isopropyl acetate, and di-isopropoxy methane. And the pH of IPA rapidly changed by about 1.99 in ppm level concentration. Generated IPA polymers were adsorbed on the wafer surface. These polymers can occur defects, and the probability increases as the concentration increases. Scanning mobility particle sizer (SMPS) measurement system can be measured the impurity in IPA solution. The total impurity concentration was increased by the concentration of H2SO4 with the same results in both gas chromatography mass spectrometry (GCMS) and time of flight secondary ion mass spectrometry (ToF-SIMS). SMPS results can be correlated with the concentration of impurities. In this paper, IPA polymers were defined by acid contamination, and these polymers have affected the Si wafer surface. In addition, the SMPS measurement system was introduced for the detection of impurities in IPA solutions.
189
Authors: David H. Wang, Fu Ping Chen, Xiao Yan Zhang, Xi Wang, Fu Fa Chen, Sally Ann Henry, Kwang Kee Chae, Zhen Ming Chu, Feng Liu, Yang Chen, Hai Bo Lei, Li Hua Ni, Zhang Yu Yu, Ye Fang Zhu, Fang Li, Tao Zhang
Abstract: The use of highly corrosive chemicals to remove nano-particles on the surface of the wafer, results in substrate losses. This has resulted in the use of megasonics which provides acoustic cavitation to remove small particles. The megasonic wave does generate bubble cavitation which applies mechanical force to wafer structure, the violent cavitation such as transit cavitation or micro jet will damage the patterned structures [1,2]. A new megasonic technology is proposed in this paper, this technology provides stable control of bubble cavitation, without pattern damage at the different modes. The technology shows better particle performance when compared with the industry standard two-fluid nozzle cleaning technology. This Timely Energized Bubble Oscillation mode provides stable cavitation with a wide power window. It is unlike conventional megasonic which creates transit cavitation and damage when the bubble implodes. This new megasonic technology can be used to clean “sensitive” structures at 28nm and below without any pattern damage.
64
Authors: Don Dussault, F. Fournel, V. Dragoi
Abstract: Current work describes development, testing and verification of a single wafer megasonic cleaning method utilizing a transducer design that meets the extreme particle neutrality, Particle Removal Efficiency (PRE), and repeatability requirements of production scale wafer bonding and other applications requiring extremely low particle levels.
269
Authors: Ted Guo, Tsung Hsun Tsai, Chin Cheng Chien, Michael Chan, Chan Lon Yang, Jun Yuan Wu
Abstract: The present work reports some approaches to reduce the static charge defects induced during single wafer cleaning process. Increase conductivity of DIW with CO2, adding backside rinse and IPA drying sequence optimization were evidenced to be effective by surface potential difference with Quantox tool. TEM and EELS were also used for analysis of volcano-like discharge defects.
63
Authors: Kenichi Sano, Masayuki Wada, Frederik E. Leys, Roger Loo, Andriy Hikavyy, Paul W. Mertens, James Snow, Akira Izumi, Katsuhiko Miya, Atsuro Eitoku
Abstract: Strained silicon engineering was first used at the 90-nm node. Nowadays, a series of techniques has seen wide-spread use and many derivatives are available because of their ease of integration and cost-effective features [ , ]. As a main part of stressor technique, embedded SiGe-S/D technology is reported to improve the pMOSFET drive current [ , ].
173
Authors: John Niccoli, Matt Cogrono, Michelle Eastlack, Dave McCane, Craig Carlson, Erik Young, Dave Chapek
Abstract: The interaction between photo resist and highly polymerizing dry etch chemistries results in the deposition of fluoropolymers on the bevel and edge of silicon wafers. These polymers are inert to most aqueous processing chemicals, but exposure to HF lifts these polymers off the bevel. This results in migration of defects to the face of the wafers. The defects are generally found within 50mm from the edge of the wafer.
155
Authors: Michael T. Andreas, Kurt Wostyn, Masayuki Wada, Tom Janssens, Karine Kenis, Twan Bearda, Paul W. Mertens
Abstract: High velocity aerosol cleaning using ultrapure water or dilute aqueous solutions (e.g. dilute ammonia) is common in semiconductor IC fabrication [1]. This process combines droplet impact forces with continuous liquid flow for improved cleaning efficiency of sub-100nm particles. As with any physically enhanced cleaning process, improved particle removal can be accompanied by increased substrate damage, especially to smaller (<80nm) features [2]. Solvents such as N-methylpyrrolidone (NMP) and tetrahydrofurfuryl alcohol (THFA) are used for resist strip applications [3]. It is possible, and sometimes useful, to deliver these solvents through the same spray nozzle normally used for aqueous spray cleaning. In this presentation we explore the particle removal and substrate damage performance of 2-ethoxyethanol (EGEE), NMP and THFA as used in a conventional aerosol spray cleaning system
39
Authors: Miao Chun Lin, Mei Qi Wang, Joe Lai, Ren Huang, Cheng Ming Weng, J.H. Liao, Jian She Tang, Ching Hwa Weng, Wei Lu, Han Wen Chen, John T.C. Lee
Abstract: As 65nm technology in mass production and 45nm technology under development, post etch ash and
cleaning faces new challenges with far more stringent requirements on surface cleanliness and
materials loss. The introduction and integration of new materials, such as metal hard mask, creates
additional requirements for wafer cleaning due to the occurrence of new defect modes related to metal
hard mask. We have optimized a post etch ash process and developed a novel aqueous solution (AQ)
based single wafer cleaning process to address these new defect modes. Physical characterization
results and process integration electrical data are presented in this paper.
359
Authors: Jian She Tang, Wei Lu, Bo Xi, Eli Martinez, Fred Li, Alex Ko, Craig Todd, John T.C. Lee
Abstract: To address the water mark issue from hydrophobic film drying, and the stringent particle removal
requirements for the 45nm technology node and beyond, we developed a cleaner with an innovative
single wafer Marangoni dryer. The single wafer Marangoni dryer design features and process
characterization data are presented in this paper. The major results can be summarized as: (1) With
the immersion type Marangoni dryer, as the wafer is lifted out of a DIW bath, a stable and uniform
meniscus can be easily maintained, making the single-wafer Marangoni dryer ideal for drying
hydrophilic, hydrophobic or hydrophobic/hydrophilic mixed patterned wafers; (2) The new
Marangoni dryer leaves ~14nm [1] water film on the wafer after drying, therefore any dissolved or
suspended materials contained inside the water film, and potentially left on the wafer surface after
water evaporation, is less than 14nm in diameter. This feature is critical for the 45nm technology
node and beyond because 23nm particle could be killer defects at these nodes [2]; (3) Because of the
strong Marangoni flow effect, high aspect ratio features can be completely dried without leaving any
water droplets inside the trenches; therefore copper corrosion can be prevented; (4) The Marangoni
dryer uses N2 as the carrier gas, so when a wafer is lifted out of the degasified DIW bath through the
N2/IPA spray zone, it is thoroughly dried in an oxygen-free environment before exposure to the
ambient environment; (5) The Marangoni dryer is free of electrostatic charge and centrifugal force
because of the slow (2mm/s~20mm/s) wafer linear lifting speed compared to linear speed at wafer
edge during SRD.
337
Authors: Kenichi Sano, Frederik E. Leys, G. Dilliway, Roger Loo, Paul W. Mertens, James Snow, Akira Izumi, Atsuro Eitoku
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