High aspect ratio vias filled with liquid metal fill

A method of metallizing a monolithic substrate body, the method comprising the steps of:

• physically contacting a metal with a first surface of the monolithic substrate body opposite a second surface of the monolithic substrate body, wherein the metal comprises gold or a gold alloy, and the monolithic substrate body comprises sapphire;
• causing a quantity of the metal in a molten state to flow via capillary action from the first surface toward the second surface of the monolithic substrate body in a via that extends along a centerline from the first surface to the second surface, so as to define a contact angle between the metal in the molten state and a metallic wetting liner, wherein the contact angle is less than 90 degrees;
• and
• solidifying the metal in the molten state in the via to produce a solidified metal that defines an electrically conductive path between the first surface and the second surface,
• wherein the contact angle is measured at an intersection between the metallic wetting liner and a straight line that extends tangent to an outer surface of the metal in the molten state in the via without crossing over the centerline, and the straight line is oriented toward the first surface of the monolithic substrate body.