BACKGROUND

The present disclosure generally relates to image sensor devices, and particularly to image sensor devices including at least two different semiconductor materials and methods of forming the same.

There is a constant drive within the semiconductor industry to increase the performance and reduce the cost of semiconductor devices, such as photodetectors, diodes, light-emitting diodes, transistors, latches, and many other semiconductor devices. This drive has resulted in continual demands for integrating one type of semiconductor devices into another semiconductor process.

For example, in an array of photodetectors, it is advantages to make respective p-n junctions and/or p-i-n structures of the photodetectors using non-silicon semiconductor materials that typically have a low band-gap (e.g., germanium (Ge) or other III-V semiconductor materials). In the interest of cost-efficiency, it is desired to integrate such non-silicon materials into low-cost large-size silicon wafers to reduce the cost of high performance non-silicon devices. By integrating non-silicon p-n junctions and/or p-i-n structures into a silicon process, other circuitry in a system (e.g., an image sensor device) can be fabricated using a standard complementary-metal-oxide-semiconductor (CMOS) process. Moreover, when fabricating the non-silicon devices and silicon CMOS in a co-planar manner, the interconnection and integration of the whole system can be conducted in a manner compatible with standard and low-cost CMOS process.

