This wafer has an un patterned copper metalization layer.
Monocrystalline wafers with a known crystal orientation (<100> in this case) can be easily cleaved into small squares (or triangles, depending on the orientation). Traditionally, <100> wafers are used for CMOS/FET devices and <111> wafers are used for bipolar devices. Thermal oxidation, SiO2 etching, and carrier mobility can greatly differ based on orientation. I believe 100 wafers have lower hole mobility than <110> and <111>. <111> wafers have the highest packing density. <100> wafers allow field effect devices to have lower threshold voltages. Many MEMS devices use <110> or <111> wafers.