Planar Al&sngbnd;nSi and PtSi&sngbnd;nSi Schottky barriers with diffusedp‐type guard rings have been fabricated on (111) and (100) silicon surfaces. The barriers have been produced by sputtering the metals on sputter‐etched silicon surfaces. For Al&sngbnd;nSi barriers the barrier height is 0.72 eV on (111) surfaces and 0.81 eV on (100) surfaces, as determined from the forwardI‐Vcharacteristic. This difference in barrier potential has been confirmed byC‐Vmeasurements. No difference in barrier height is found for PtSi&sngbnd;nSi barriers made on (111) and (100) surfaces. A qualitative explanation is given for the experimental results in terms of strong or weak coupling of surface states to the metal.