Si-H bond production by NH3 adsorption on Si(111): An UPS study

Thermal stability of trimethyl indium on Si(100)(2 × 1) as studied with HREELS, UPS and XPS: a comparison with the results from Si(111)(7 × 7) and Si(110) studies

“…In an STM study, Avouris et al [ 11] concluded that the rest-atoms are electron richer than the adatoms because of the change transfer from the latter to the former. They also found that the rest-atoms are more reactive towards the adsorbed NH3 at room temperature, which is also observed by Kubler et al [12] in their UPS study of NH3 on Si(i11). In the present study, however, we found that the S1 state was attenuated first and then the S2 state as the TMIn was continuously introduced onto the Si (111)-7x7 surface at 110 K. This is clearly shown in Figure 3, where the peak at -0.2 eV below EF due to the S1 state is essentially vanished at 0.3 L dosage; at this dosage the peak at 0.8 eV below EF juststarted to decrease, but it vanished totally at ~-1 L.…”

The Adsorption and Thermal Composition of N2H4 and CH3N2H3 on Si(111)- 7x7

“…Such a shift was also observed when NH 3 dosed Si surfaces were annealed at higher temperatures [10,14,15]. The small but noticeable increase in the Njs XPS peak intensity at higher annealing temperatures is most likely due to the readsorption of N-containing species desorbed from the surrounding surfaces of the sample holder which are also warmed during the sample annealing procedure as well as residual gases in the chamber.…”

“…However, other than for macroscale information, very little has been published about these potential nitridants regarding the reaction mechanism under various conditions of submonolayer coverage and temperature. Thus, considering the fundamental and technological nature of such processing and the recently increased interests in the Sinitridation process [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21], a more thorough investigation is important and necessary.…”

“…In view of the limited available information on the use of hydrazine or its alkyl derivatives in Si-nitridation and in order to compare the present reaction mechanism investigation, it is worthy to consider a number of other surface studies on Sinitridation using various nitridants; these include the interaction of NH 3 with porous Si [5], NH 3 on Si(111) [6][7][8][9][10][11] and Si(100) [12][13][14][15], N 2 + on Si(111) [16], N on Si(111) [11,171 and Si(100) [11], NO on Si(111) [9,10,18] and Si(100) [19], and, more recently, HN 3 on Si(110) [20] and Si(111) [21].…”

“…Briefly, in the above cases of H-containing nitridants [5][6][7][8][9][10][11][12][13][14][15]20,21), it is generally agreed that H-adatoms passivate the Si surface at temperatures below -800 K following dissociative adsorption; above this temperature, desorption of H takes place with the resulting formation of a variety of proposed SixNy structures beginning with a near planar or deformed planar Si 3 N [17,18]. For the other nitridants, a similar SiN structure has been proposed to form on the Si surface in the 600-800 K temperature range.…”