Version of CMOS
The 4011 is a standard 4000 series CMOS IC with four independent, two-input NAND gates.
Figure: NAND Gate Diagram in a CMOS Type 4011 Integrated Circuit.
Availability
Most semiconductor companies, such as Fairchild Semiconductor, Philips, and Texas Instruments, sell these devices. These are typically available in both through-hole DIL and SOIC configurations. Most datasheet databases have datasheets readily available.
https://www.apogeeweb.net/electron/what-is-a-nand-gate.html
