In our previous work, we have shown that diffraction of matter-wave from a square-wave graing of  400-μm period and 10-μm wide strips results mainly from scattering off a periodic array of parallel half-planes. This phenomenon is understood as multiple diffractions of waves at those half-planes. In addition, the transition of reflection or diffraction mechanisms from quantum reflection to half-plane array diffraction has been studied with decreasing strip width as well. 
 Here, we study how the interaction of the matter-wave with the grating surface of a finite width affects the half-plane array diffraction. The interaction induces an additional phase shift along the path of the matter-wave, and, therefore, reduces the diffraction efficiency. The interaction effects appear differently for He and D2, for gratings of different period with the same strip width, and for He atoms of different de Broglie wavelengths.