CMOStransistorer

CMOStransistorer, commonly written as CMOS transistor, refers to the metal-oxide-semiconductor field-effect transistor used in complementary metal-oxide-semiconductor circuits. A CMOS transistor is created in pairs of n-type (NMOS) and p-type (PMOS) MOSFETs that share a common input and are connected to pull outputs toward supply rails. The basic CMOS logic inverter uses a PMOS transistor connected to the supply voltage and an NMOS transistor connected to ground, with the output taken from the junction of the two devices. When the input is low, the PMOS conducts and the NMOS is off, pulling the output high; when the input is high, the NMOS conducts and the PMOS is off, pulling the output low.

The primary advantage of CMOS technology is its low static power consumption. At any steady logic level, one transistor is off, so only leakage currents contribute to static power. Dynamic power is consumed during switching as the output capacitance is charged and discharged, and it scales with the square of the supply voltage and the switching frequency. CMOS devices also offer high noise margins and strong drive capabilities, enabling high-density integration.

Fabrication involves silicon wafers with doped regions to form NMOS and PMOS transistors, insulated gates typically by silicon dioxide, and patterned interconnects. Modern nodes often use advanced gate materials, such as high-k dielectrics and metal gates, and increasingly employ multi-gate architectures like FinFETs to improve control, reduce leakage, and sustain performance at small geometry.

CMOS transistors are the cornerstone of contemporary digital electronics, powering microprocessors, memory cells, and a wide range of integrated circuits due to their combination of low static power, scalability, and performance.