Group IV semiconductor surface chemistry: A multiple internal reflection infrared spectroscopy study
The adsorption of Si[sub 2]H[sub 6], Ge[sub 2]H[sub 6], and hydrogen (atoms) on Ge(111) and Si(100) surfaces are characterized by using multiple internal reflection infrared spectroscopy (MIRIRS). The inherent high resolution or infrared spectroscopy and the application of polarized light enable the detection of important modes for resolving the structure of surface species. The choice of Ge as substrate has extended the low frequency limit for MIRIRS to below 700 cm[sup [minus]1] (in comparison to that of Si at 1450 cm[sup [minus]1]). The vibrational modes in this low frequency region are used to uniquely measure the extent of Si[sub 2]H[sub 6] and Ge[sub 2]H[sub 6] dissociation on Ge(111). Si[sub 2]H[sub 6] and Ge[sub 2]H[sub 6] interact similarly with the Ge(111) surface. Molecular adsorption is the dominant process below 120K. Complete dissociation occurs above 150K to produce adsorbed trihydrides, SiH[sub 3] and GeH[sub 3], respectively. Adsorbed SiH[sub 3] decomposes at temperatures [ge] 200K to form SiH[sub 2], SiH and GeH, while surface GeH[sub 3] decomposition produces only GeH[sub 2] and GeH. Decomposition of all surface hydrides occurs by 600K. The adsorption of atomic hydrogen on Ge(111) leads to the production of GeH[sub 3], GeH[sub 2] and GeH at low temperatures ([le]200K), and strictly monohydrides at temperatures [ge]400K. Atomic hydrogen occupies primarily a single adsorption site at 500K, while a variety of adsorption sites are populated at lower adsorption temperatures. The reaction of H atoms with Si(100) - 2 [times] 1 produces Si(100) - 2 [times] 1:H, 3 [times] 1:H, and 1 [times] 1:H, sequentially, depending on the exposure and adsorption temperatures. The highly repulsive interaction between SiH[sub 2] groups prohibits the formation of a pure 1 [times] 1 dihydride phase, and induces the preferential formation of SiH[sub 3] at low temperatures ([le]150K).
- Research Organization:
- California Univ., San Diego, La Jolla, CA (United States)
- OSTI ID:
- 5721463
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Adsorption and thermal reactions of disilane and the growth of Si films on Ge(100)-(2[times]1)
Atomic H abstraction of surface H on Si: An Eley--Rideal mechanism
Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
GERMANIUM
SORPTIVE PROPERTIES
GERMANIUM HYDRIDES
ABSORPTION SPECTROSCOPY
SILANES
SILICON
DISSOCIATION
MILLER INDICES
MOLECULAR STRUCTURE
REFLECTION
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
VIBRATIONAL STATES
ELEMENTS
ENERGY LEVELS
EXCITED STATES
GERMANIUM COMPOUNDS
HYDRIDES
HYDROGEN COMPOUNDS
METALS
ORGANIC COMPOUNDS
ORGANIC SILICON COMPOUNDS
SEMIMETALS
SILICON COMPOUNDS
SPECTROSCOPY
SURFACE PROPERTIES
TEMPERATURE RANGE
400102* - Chemical & Spectral Procedures