CMOS Technology
The most common description of the evolution of CMOS technology is known as Moore’s law. In 1963 Gordon Moore predicted that the transistor count would double every 18 months. The observation made by Gordon Moore was that the number of components on the most complex integrated circuit chip would double each year for the next 10 years. Frank Wanlass at Fairchild described the first CMOS logic gate (nMOS and pMOS) in 1963. Developments in complementary metal oxide semiconductor (CMOS) technology allow the sensors to penetrate into high-performance applications that were previously not practical. In the eighties, CMOS processes were widely adopted. Present day chips would not exist if the CMOS technique would not have been implemented around the late eighties.
CMOS sensors were known for their fast speeds, but less for image quality. The newest CMOS sensors now combine both high speed and excellent image quality, and are rapidly becoming more popular in both area-scan and line-scan machine-vision applications. CMOS sensors are characterized by having parts of the electronics, the read-out system and the illumination control located directly adjacent to the photosensitive surface. One main advantage of this design is that each pixel can be controlled and read out directly. One drawback is that a part of each pixel is occupied by electronic components, which reduces the fill factor. CMOS technology allows a variety of both analogue and digital functions to be integrated directly into the sensor. This means that analogue data can be amplified and converted into a digital signal right on the chip. Memory, timing generators and other preprocessing steps can also be integrated.
A new approach for line-scan image sensors had to be found to overcome some limitations that came with the development of the CMOS technology. Before the 1990s, CMOS technology suffered from low lithography resolution and the absence of fabrication processes needed for imaging sensors. With the arrival of CMOS active pixel sensor (CMOS-APS) technology, the sensors were virtually reinvented. CMOS-APS sensors rapidly became the first choice for high-speed area-scan imaging applications, in particular those with the column parallel ADC architecture introduced a decade ago. Modern CMOS sensors not only exhibit superior performance in speed, but are more price-attractive due to lower production costs. The latest CMOS sensor generation also exhibits excellent image quality. Due to improvements in chip fabrication technology, recent developed CMOS sensors have excellent noise and homogeneity characteristics.
The technological advancement of CMOS over the years now uses flash memory, which is a form of EEPROM instead of chips. CMOS processes, memories and variants have become dominant due to the fact that circuitry dissipates less power than logic families with resistive loads. This technology has therefore become the vast majority of modern integrated circuit. The CMOS RAM and the real-time clock have been integrated as a part of the Southbridge chipset and it may not be a standalone chip on modern motherboards. The size of the CMOS memory has stayed the same because there has been no need to increase the size more than 512 bytes in the memory as it holds the absolute basic boot settings for the system. CMOS still uses a small battery in case there is a power outage and still uses volatile RAM.

References http://optics.org/article/36630 http://www.engineersgarage.com/articles/what-is-cmos-technology