Conservation of the Optical Properties of SRO after CMOS IC Processing

The Silicon rich silicon oxide (SRO) is a CMOS compatible material that present light emission properties when annealed at high temperatures to produce the silicon segregation process. This material can be used to integrate optoelectronics circuits. However, during the CMOS fabrication process there are thermal processes that could alter the characteristics of this material. Moreover, in the same way thermal treatments needed for efficient light emission in the SRO could damage the electronic circuits. Then, special care has to be paid when SRO devices with optical functions and CMOS with electronic control circuits are integrated. In this paper, it is shown how a silicon sensor cover with a SRO layer and various electronic CMOS circuits were fabricated simultaneously. Details of how the SRO film was protected to avoid it to be damage, and how the SRO film was deposited and annealed in order to maintain the electronic circuitry working, are given. Experimental details of the optical properties and the electronic functionality are displayed. So, it is possible to integrate the SRO film and electronic functions in silicon IC successfully.