Fabrication of all-solid-state energy storage devices

A semiconductor device structure comprising:

• a silicon substrate having at least one trench disposed therein, the at least one trench providing an energy storage device containment feature;
• an electrical and ionic insulating layer disposed over at least a top surface of silicon substrate;
• and
• a plurality of energy storage device layers within the at least one trench, the plurality of energy storage device layers comprising at least a composite cathode-based active electrode having a thickness of at least 100 nm and an internal resistance of less than 150 Ohms/cm2.

A method of forming a semiconductor device structure, the method comprising:

• forming at least one trench in a silicon substrate, the at least one trench providing an energy storage device containment feature;
• forming at least one electrical and ionic insulating layer over at least a top surface of the silicon substrate;
• and
• forming a plurality of energy storage device layers within the at least one trench, wherein each layer of the plurality of energy storage device layers is independently processed and integrated into the at least one trench, wherein one or more of thermal, electrical, and pressure parameters of the independently processed energy storage device layers are controlled by sidewalls and a base of the at least one trench, wherein forming the plurality of energy storage device layers comprises:
• forming a porous silicon layer of unitary construction with a p+ type silicon substrate, wherein the porous silicon layer provides at least a portion of a first active electrode for an energy storage device disposed in the energy storage device containment feature.