ATOMIC-SCALE EXTRACTION OF HYDROGEN-ATOMS ADSORBED ON SI(001) WITH THE SCANNING TUNNELING MICROSCOPE

Atomic scale extraction of hydrogen atoms on Si(001)-(2 x 1)-H and -(3 x 1)-H surfaces between 300 and 610 K have been studied using a scann ing tunneling microscope. Hydrogen atoms were extracted at positive an d negative sample bias voltage. Site-selective desorption and reconstr uction from the dihydride phase to the monohydride phase are found in the desorption of hydrogen atoms from Si(001)-(3 x 1)-H surfaces. STM- induced desorption of H atoms on a Si(001)-(3 x 1)-H surface occurs pr eferentially at dihydride units rather than monohydride units. The res ults support an electric field induced desorption. (C) 1997 Elsevier S cience B.V.