Mechanism of GeH4 dissociation on Si(1 1 1)-(7 × 7)

Results of an STM study of dissociative GeH4 adsorption on Si(1 1 1)-(7 × 7) at 300 K show that GeH4 adsorbs under scission of two Ge–H bonds according to GeH4(g) + 4db → GeH2(ad) + 2H(ad). GeH2 binds to two adatom dangling bonds in a bridged configuration, while the two released hydrogen atoms saturate two additional dangling bonds. The GeH4 sticking coefficient under these conditions is 1.2 × 10−6, one order of magnitude smaller than for SiH4.