Ultra-High Vacuum Cells Realized by Miniature Ion Pump Using High-Efficiency Plasma Source.

In recent years, there has been significant interest in quantum technology, characterized by the emergence of quantum computers boasting immense processing power, ultra-sensitive quantum sensors, and ultra-precise atomic clocks. Miniaturization of quantum devices using cold atoms necessitates the employment of an ultra-high vacuum miniature cell with a pressure of approximately 10 Pa or even lower. In this study, we developed an ultra-high vacuum cell realized by a miniature ion pump using a high-efficiency plasma source.

High-Efficiency Plasma Source Using a Magnetic Mirror Trap for Miniature-Ion Pumps.

In this study, we design a highly efficient plasma source using a magnetic mirror trap with two opposing permanent magnets for a miniature high-efficiency ion pump. First, we simulated the distribution of the magnetic field line formed by the proposed magnetic mirror configuration. By optimizing the distance between two opposing permanent magnets and size of these magnets, a magnetic mirror ratio value of 27 could be obtained, which is an electron confinement efficiency of over 90%.

Wafer-Scale Room-Temperature Bonding of Smooth Au/Ti-Based Getter Layer for Vacuum Packaging.

This study demonstrates room-temperature bonding using a getter layer for the vacuum packaging of microsystems. A thick Ti layer covered with an Au layer is utilized as a getter layer because it can absorb gas molecules in the package. Additionally, smooth Au surfaces can form direct bonds for hermetic sealing at room temperature.

Bonding formation and gas absorption using Au/Pt/Ti layers for vacuum packaging.

In this study, we developed a metal multilayer that can provide hermetic sealing after degassing the assemblies and absorbing the residual gases in the package. A package without a leak path was obtained by the direct bonding of the Au/Pt/Ti layers. After packaging, annealing at 450 °C caused thermal diffusion of the Ti underlayer atoms to the inner surface, which led to absorption of the residual gas molecules.

Low-temperature direct bonding of InP and diamond substrates under atmospheric conditions.

An InP substrate was directly bonded on a diamond heat spreader for efficient heat dissipation. The InP surface activated by oxygen plasma and the diamond surface cleaned with an NH/HO mixture were contacted under atmospheric conditions. Subsequently, the InP/diamond specimen was annealed at 250 °C to form direct bonding.

Effect of Au Film Thickness and Surface Roughness on Room-Temperature Wafer Bonding and Wafer-Scale Vacuum Sealing by Au-Au Surface Activated Bonding.

Au-Au surface activated bonding (SAB) using ultrathin Au films is effective for room-temperature pressureless wafer bonding. This paper reports the effect of the film thickness (15-500 nm) and surface roughness (0.3-1.

Comparison of Argon and Oxygen Plasma Treatments for Ambient Room-Temperature Wafer-Scale Au⁻Au Bonding Using Ultrathin Au Films.

Au⁻Au surface activated bonding is promising for room-temperature bonding. The use of Ar plasma vs. O₂ plasma for pretreatment was investigated for room-temperature wafer-scale Au⁻Au bonding using ultrathin Au films (<50 nm) in ambient air.