We present the results of our project aimed to design and construct silicon grisms. The fabrication of such devices is a complex and critical process involving litho masking, anisotropic etching and direct bonding techniques. After the successful fabrication of the silicon grating, we have optimized the bonding of the grating onto the hypotenuse of a silicon prism to get the final prototype. After some critical phases during the experimentation a silicon grism has been eventually fabricated with 363.6 grooves/mm and 14 degrees of blaze angle. The results of the cryo-optical laboratory tests are reported, along with a general description of the adopted technological process. The positive results allows us to offer to the international community a new capability in building such devices.