TP: Atmospheric Plasma

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Metallurgy, Surface Preparation and Bonding for Cryogenic and Superconducting Hybrid Applications This Paper by the Quantum Computing groups at Google and UCSB describes the materials and processes (including SET hybrid bonders and Ontos Atmospheric Plasma) which are now routinely used to produce leading-edge quantum computing components operating at superconducting temperatures. Qubit compatible superconducting interconnects

Evaluating Surface Wettability for SET-NA Ontos7 Atmospheric Plasma Treated Samples This technical paper, published with the kind permission of ULTRA Communication, presents the wetting evaluation results of Surface Preparation using the Ontos Atmospheric Plasma System Evaluating Surface Wettability for Ontos Ontos7 Treated Samples (2017)

Semiconductor Processing With ONTOS7 Surface Preparation Surface Preparation applied to Semiconductor processing using the Atmospheric Plasma System ONTOS7 Semiconductor Processing with Ontos7 (2017)

Utilization of Atmospheric Plasma Surface Preparation To Improve Copper Plating Processes Many process steps in semiconductor manufacturing and packaging benefit from pristine surface preparation, such as descuming of photoresist, removal of native oxides, and surface activation. One particularly important surface process is the preparation of surfaces prior to copper plating. ESTC 2016 publication, re-posted with the Authorization of IEEE.

Pure Chemical Reduction of Tin Oxides to Metallic Tin by Atmospheric Plasma to Improve Interconnection Reflow of Pb-free Solders Tin alloys are widely used as solder for electronic interconnections. Tin solder surfaces tend to have tin oxides which need to be removed to improve the yield of interconnection reflow processes such as flip chip joining. Conventionally, a strong flux is employed to remove these oxides, however this process has the drawbacks of leaving flux residue which can cause underfill delamination or require a high-cost cleaning process. As solder bump volumes and bump-to-bump spacing decrease, these problems become more difficult to manage in manufacturing. We propose the use of Atmospheric Plasma to reduce these oxides from the bump surfaces to enable the use of very light fluxes, or no flux at all. IMAPs 2017 publication, re-posted with the Authorization.

Interconnect Structure for Room Temperature 3D-IC Stacking employing Binary Alloying for High Temperature Stability We propose depositing Ni\In onto the Cu post on one side of the bond interface, and Ni\Ag to the other side to create a metallurgical system which can be bonded at room temperature to create robust mechanical and electrical interconnects. An Atmospheric Plasma process is used to de-oxidize and passivate the In and Ag surfaces, followed by room temperature compression bonding of the In to Ag. Subsequent chip layers can be stacked in the same manner at room temperature without requiring thermal excursions for melting and solidification. Following completion and test of the stacked assembly, solid-state annealing will alloy the In and Ag layers, raising the melt temperature of the In/Ag alloy to above standard solder assembly temperatures. IWLPC 2013 publication, re-posted with the Authorization.

Characterization of a Novel Fluxless SurfacePreparation Process for Die InterconnectBonding For applications such as 3D integration, flip chip, and other die interconnection processes, a variety of metals is used to form an electrical and mechanical bond between the two components. ECTC 2012 publication, re-posted with the Authorization.

AU Bonding An unexpected bonding benefit was discovered while bonding Gold pads to Gold pads for a flip-chip configuration. Low-temperature compression bonding (necessitated by chip temperature restrictions to 200C) had yielded very poor adhesion between Gold pads, even though there was significant visual pad-to-pad compression Gold to Gold Direct Bonding
Competitive Advantages of Ontos7 Atmospheric Plasma This document highlights the Advantages of Ontos7 Atmospheric Plasma Process over Vacuum RIE Plasma for Die/Wafer Surface Preparation, and over Competitive Atmospheric Plasma Products for the Preparation of Semiconductor Surfaces. Competitive Advantages of Ontos7 Atmospheric Plasma Presentation