FIGS 4A and 4C show {HEAD ~ transfer devices} which hold {TAIL ~ the semiconductor wafers} vertically while FIG 4B shows a transfer device which holds the semiconductor wafers horizontally 
hold
FIGS 4A and 4C show { HEAD ~ transfer devices } which hold { TAIL ~ the semiconductor wafers } vertically while FIG 4B shows a transfer device which holds the semiconductor wafers horizontally
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH