1. History and Advancements in CMOS Technology:
– Complementary symmetry principle introduced by George Sziklai in 1953.
– MOSFET invented by Mohamed M. Atalla and Dawon Kahng at Bell Labs in 1959.
– Development of CMOS technology by Chih-Tang Sah and Frank Wanlass at Fairchild in 1963.
– RCA commercialized CMOS in the late 1960s.
– Toshiba’s C²MOS technology with lower power consumption in 1969.
– Hitachi’s twin-well Hi-CMOS process in 1978.
– CMOS processors dominance in the 1980s.
– Intel’s 1.5 μm CMOS fabrication process in 1983.
2. Characteristics and Physical Structure of CMOS Devices:
– High noise immunity and low static power consumption.
– High integration density of logic functions on a chip.
– CMOS based on metal–oxide–semiconductor field-effect transistors.
– Use of metal gate electrode on oxide insulator.
– Widely used in digital, analog, and mixed-signal ICs.
– CMOS processes dominate modern integrated circuit manufacturing.
3. CMOS Logic and Power Consumption:
– CMOS circuits use a combination of p-type and n-type MOSFETs.
– Logic design involving AND and OR gates.
– Lower power consumption compared to NMOS and TTL logic.
– Dynamic power dissipation due to charging and discharging of load capacitances.
– Static power efficient when idle.
4. Applications and Innovations in CMOS Technology:
– Utilization in analog and mixed-signal applications.
– RF CMOS for wireless communication systems.
– Temperature range of operation and advancements in high mobility materials.
– Intel’s advancements in CMOS technology.
– Various applications in different fields such as RF circuits and DRAM sense amplifiers.
5. Advanced CMOS Technologies and Research:
– Single-electron MOS transistors and their unique applications.
– Input protection mechanisms in CMOS circuits.
– Leakage reduction methods in nanometer CMOS technologies.
– Timing-aware power optimization in CMOS circuit design.
– Studies on high mobility materials for CMOS applications and their impact on circuit design.
Complementary metal–oxide–semiconductor (CMOS, pronounced "sea-moss", /siːmɑːs/, /-ɒs/) is a type of metal–oxide–semiconductor field-effect transistor (MOSFET) fabrication process that uses complementary and symmetrical pairs of p-type and n-type MOSFETs for logic functions. CMOS technology is used for constructing integrated circuit (IC) chips, including microprocessors, microcontrollers, memory chips (including CMOS BIOS), and other digital logic circuits. CMOS technology is also used for analog circuits such as image sensors (CMOS sensors), data converters, RF circuits (RF CMOS), and highly integrated transceivers for many types of communication.
The CMOS process was originally conceived by Frank Wanlass at Fairchild Semiconductor and presented by Wanlass and Chih-Tang Sah at the International Solid-State Circuits Conference in 1963. Wanlass later filed US patent 3,356,858 for CMOS circuitry and it was granted in 1967. RCA commercialized the technology with the trademark "COS-MOS" in the late 1960s, forcing other manufacturers to find another name, leading to "CMOS" becoming the standard name for the technology by the early 1970s. CMOS overtook NMOS logic as the dominant MOSFET fabrication process for very large-scale integration (VLSI) chips in the 1980s, also replacing earlier transistor–transistor logic (TTL) technology. CMOS has since remained the standard fabrication process for MOSFET semiconductor devices in VLSI chips. As of 2011[update], 99% of IC chips, including most digital, analog and mixed-signal ICs, were fabricated using CMOS technology.
Two important characteristics of CMOS devices are high noise immunity and low static power consumption. Since one transistor of the MOSFET pair is always off, the series combination draws significant power only momentarily during switching between on and off states. Consequently, CMOS devices do not produce as much waste heat as other forms of logic, like NMOS logic or transistor–transistor logic (TTL), which normally have some standing current even when not changing state. These characteristics allow CMOS to integrate a high density of logic functions on a chip. It was primarily for this reason that CMOS became the most widely used technology to be implemented in VLSI chips.
The phrase "metal–oxide–semiconductor" is a reference to the physical structure of MOS field-effect transistors, having a metal gate electrode placed on top of an oxide insulator, which in turn is on top of a semiconductor material. Aluminium was once used but now the material is polysilicon. Other metal gates have made a comeback with the advent of high-κ dielectric materials in the CMOS process, as announced by IBM and Intel for the 45 nanometer node and smaller sizes.
