Wafer-scale fabrication of evacuated alkali vapor cells

TL;DR

This paper presents a wafer-scale fabrication process for alkali vapor cells with low residual gas pressure, enabling cost-effective production of atomic devices like clocks and sensors.

Contribution

It introduces a novel etching technique to produce low-pressure alkali vapor cells at wafer scale, improving yield and potential for mass production.

Findings

Residual gas pressure below 0.5 kPa achieved

Yield of over 50% in fabrication process

Potential for low-cost chip-scale atomic devices

Abstract

We describe a process for fabricating a wafer-scale array of alkali metal vapor cells with low residual gas pressure. We show that by etching long, thin channels between the cells on the Si wafer surface, the residual gas pressure in the evacuated vapor cell can be reduced to below 0.5 kPa (4 Torr) with a yield above 50 %. The low residual gas pressure in these mass-producible alkali vapor cells can enable a new generation of low-cost chip-scale atomic devices such as vapor cell optical clocks, wavelength references, and Rydberg sensors.