An extremely small piece of silicon on which integrated circuits are fabricated are called:

An integrated circuit (IC), also called a chip or microchip, is a small grouping of electronic circuits designed on a small flat piece of semiconductor material, typically silicon.

• Card Reader: This is a hardware device used to read data from storage media (like credit cards or SD cards); it is not the substrate for an integrated circuit.
• Feed: In computing, this generally refers to a data format used for providing users with frequently updated content (like an RSS feed) or the act of providing power/material to a machine.
• Hollerith Code: This is a specific system of encoding data on punched cards, named after Herman Hollerith; it predates modern silicon-based integrated circuits.