Not quite. Leakage current in CMOS circuits became the dominant source of power consumption around the 90 nm and 65 nm nodes, long before quantum tunneling was

Not quite. Leakage current in CMOS circuits became the dominant source of power consumption around the 90 nm and 65 nm nodes, long before quantum tunneling was a major factor, and often exceeded dynamic switching power. This led to the introduction of multiple threshold-voltage devices and body-biasing techniques to dynamically adjust Vt and curb static leakage.