In0.53Ga0.47As/InP avalanche photodiodes (APDs) with separate absorption and multiplication (SAM) regions have been grown by gas-source molecular beam epitaxy (GSMBE). These mesa-structure diodes, with a mesa diameter of 150 μm, exhibit a very low dark current of 17 nA, and primary unmultiplied dark current of less than 1.0 nA at 90% of the breakdown voltage. A gain as high as 100 is observed near the breakdown. Good uniformities of punch-through voltage and breakdown voltage were obtained on a 16 mm×16 mm wafer. Also, a premature breakdown was observed in the In0.53Ga0.47As/InP SAM-APDs with a V-shaped defect density of 25,000 cm-2.