Back-illuminated sensor
Rear Exposure (English: backside illumination, BSI) is a construction variant in the development of solid-state image sensors.
Technology
The light is incident after passing through the camera lens the light-sensitive silicon crystal directly and from the back, while in the variant frontside illumination, the light only passes through the area of the Metallisierungschichten before it generates electric charges in the silicon.
Characterized there is a part of the active area " in the shadow " of the sensor is less sensitive. In the first CMOS sensor more area was covered by the wiring than a CCD, a change of direction of the light is more effective than the more sensitive CCD.
Areas of application
Both variants are used in CMOS and CCD sensors. While frontside illumination is used in commercial digital cameras, has been the backside illumination special applications such as astronomy, especially in the reserved range of ultraviolet light, compare front - vs. Back-illuminated. It is represented on the Hubble Space Telescope a BSI CCD for UV photography.
Semiconductor manufacturers have announced the start of mass production of CMOS back -side illumination sensors for 2009. The advantages of this arrangement are intended to be for CMOS sensors in an improved image quality and a higher proportion of the light- active area of the sensor.
Sony builds since April 2011 BSI sensors in their phones. These sensors are touted as Exmor R sensors.
On September 13, 2012, the new iPhone 5 has been presented with a backside illuminated sensor. Erroneously, he is being touted by the press as a backlit sensor.
Nokia is building a BSI sensor in its Pure View camera in the Lumia 920, and in the 41- megapixel camera Lumia 1020.