Color filter process is after passivation layer technology. Front end wafers may be produced by different size masks. For example, if front end stepper were 5" mask system, but color filter production line is 6 " mask, throughput will be very slow (6" mask but is 5" layout). Different foundries used different size masks & stepping systems (avoid guard ring) for production caused more complicated for different size masks matching. Color process use high energy, so may impact stepper throughput & Lens quality also. Improve throughput & prolong Lens life are very important for production. Using the matching system we can improve stepper (Example: 5"layout changed to 6" layout on 6" mask) throughput effectively & prolong ASML lens life.
This paper is about the definition and requirement of Compact lens system. One important application of the CMOS image sensor module is to capture a still image or continuous images when it is bundled with cellular phones (embedded, not add-on module). This type of application is related to the so-called “compact lens system.” We will make a description of image forming at pixel and image forming at chip and introduce the experiments of microlens shift. The discussion of the experimented results will include several factors: a) the color filter stack thickness b) the IC stack thickness c) fill factor d) the shape of photo diode. At last, check what problems may happen in actual microlens shift applications. From all above, we can understand the requirement of compact lens system.