Thermally-insulated micro-fabricated atomic clock structure and method of forming the atomic clock structure

摘要

A micro-fabricated atomic clock structure is thermally insulated so that the atomic clock structure can operate with very little power in an environment where the external temperature can drop to −40° C., while at the same time maintaining the temperature required for the proper operation of the VCSEL and the gas within the vapor cell.

主权项

1. A semiconductor structure comprising:
a photodiode structure including: a substrate having a conductivity type, a device surface, a non-device surface, and a thermal barrier opening that extends into the substrate from the non-device surface; a number of circuit elements that lie within the substrate; a metal interconnect structure that touches the substrate, the metal interconnect structure making electrical connections to the number of circuit elements to realize a photodiode circuit; wherein the thermal barrier opening exposes the metal interconnect structure; wherein the thermal barrier opening horizontally surrounds the number of circuit elements; wherein the semiconductor structure further comprises a package electrically connected to the metal interconnect structure, the substrate lying within the package, an air pressure within the thermal barrier opening being less than an atmospheric pressure outside of the package; wherein the metal interconnect structure further includes: a first non-conductive layer that touches the device surface of the substrate; a plurality of contacts that extend through the first non-conductive layer to make electrical connections to the number of circuit elements; a plurality of metal-1 traces that touch the first non-conductive layer and the plurality of contacts; a second non-conductive layer that touches the first non-conductive layer and the plurality of metal-1 traces; a plurality of vias that extend through the second non-conductive layer to make electrical connections to the number of metal-1 traces; and a plurality of metal-2 traces that touch the second non-conductive layer and the plurality of vias, the plurality of metal-2 traces having a thermal conductivity that is greater than a thermal conductivity of the metal-1 traces.