The crystal-Si and poly-Si fin-channel flash memories with a thin n +-poly-Si floating-gate (FG) layer have successfully been fabricated, and their electrical characteristics have systematically been investigated. It was experimentally found that the better short-channel effect (SCE) immunity, the smaller threshold voltage (V t) variations and a higher program speed are obtained in the crystal-Si fin-channel tri-gate (TG)-type flash memories than in the double-gate (DG)-type ones. It was also confirmed that split-gate crystal-Si fin-channel flash memories show highly suppressed over-erase as compared to that in stack-gate memories. Moreover, it was found that V t variation in the poly-Si fin-channel flash memories after a program/erase (P/E) cycle became comparable to that in the crystal-Si fin-channel memories. The measured source-drain breakdown voltage (BV DS) was higher than 3.2 V even the gate length (L g) was down to 76 nm. The developed technology is very useful for the fabrication of scaled NOR-type flash memory.