After two decades in development, chipmakers are making a costly bet on a technology that will cram even more transistors onto silicon. Their success may hinge on a little-known company in Yokohama.

Lasertec Corp. is the world's sole maker of equipment that tests glass squares slightly bigger than a CD case that act as a stencil for chip designs. By shining light through the squares, circuits smaller than the width of a few strands of DNA are imprinted onto silicon wafers in a process called lithography.

These templates have to be perfect: Even a tiny defect can make every single chip in the batch unusable.