We fabricated quasi-one-dimensional (1D) quantum wells on the Si(100) surface by using a scanning tunneling microscopy (STM) tip. Electron waves were confined to a single silicon dimer row by two tungsten nanodots that were separated by several nanometers. The tungsten dots were deposited by point contact between the STM tip and the sample. The size of the dots we created on the Si(100) surface was as small as the width of a single dimer. Differential conductance mapping and scanning tunneling spectroscopy detected different quantum states confined to the quasi-1D quantum well as changing bias voltage. (c) 2006 American Institute of Physics.