Selectivity Mechanisms in Low Pressure Selective Epitaxial Silicon Growth

Abstract

Selective silicon processing at 775 and 850~ using an SiH2C1JHC1/H2 based chemistry was studied. The selectivity of 2 each experimental condition was quantified by measuring the silicon nuclei density/cm on large blanket areas of SiO2. The morphology of the selective silicon films was examined for texture and hillocks. The roles of water vapor and atomic hydrogen on the microchemistry of an SiO2 surface was investigated. Thermodynamic modeling of the effect of different atmospheric leak rates on the water vapor and atomic hydrogen concentrations was carried out with the aid of the SOLGAS program. A new understanding of selectivity is proposed. An SiO2 surface is an interruption of the bulk continuous random network structure and, as such, has a characteristic density of defect sites. The degree of selectivity observed is determined by the type of species which terminate these defect sites, i.e., by the number of defect sites which are not chemically passivated against the adsorption of silicon species. A universal selective silicon processing regime is predicted and good agreement with a wide range of published selective silicon processes is shown.

Selective epitaxial growth of Si and SiGe for metal oxide semiconductor transistors

“…It is indeed possible using reduced deposition pressures combined with this chlorinated chemistry to selectively grow high quality Si [9][10][11][12] and SiGe [12][13][14][15][16][17][18][19][20][21][22][23][24] layers inside the windows of SiO 2 or Si 3 N 4 -masked Si wafers. RPs minimize autodoping [9,25].…”

Lateral overgrowth of germanium for monolithic integration of germanium-on-insulator on silicon

“…3(c)). This number is more than 10 Â improvement over the previously reported value from bulk growth [24,26] and shows that TDD is effectively suppressed by defect necking. Raman spectroscopy is used to measure the in-plane strain (Table 2).…”

“…SiO 2 and low pressure chemical vapor deposition (LPCVD) silicon nitride (Si 3 N 4 ) grown or deposited under different conditions were tried as growth masks. Unlike SiO 2 , Si 3 N 4 provides poor growth selectivity similar to Si selective growth [24]. Although low temperature silicon oxides (LTOs) do not provide decent selectivity, selectivity can be improved when the LTOs are densified at high temperature (higher than 1000 1C).…”

Agglomeration control during the selective epitaxial growth of Si raised sources and drains on ultra-thin silicon-on-insulator substrates

“…One of the most critical steps in such thin film SOI device fabrication is the silicon selective epitaxial growth (SEG) which is mandatory for the formation of Raised Sources and Drains [8][9][10][11]. A traditional epitaxial growth process consists first of all of a ''HF-last'' ex situ wet cleaning, resulting in a hydrogen terminated surface with a sub-monolayer coverage by oxygen, fluor and carbon atoms [12], a high-temperature in situ cleaning, used to form an atomically clean Si surface fit for some epitaxial growth and finally a chemical vapour deposition (CVD) step.…”

“…A traditional epitaxial growth process consists first of all of a ''HF-last'' ex situ wet cleaning, resulting in a hydrogen terminated surface with a sub-monolayer coverage by oxygen, fluor and carbon atoms [12], a high-temperature in situ cleaning, used to form an atomically clean Si surface fit for some epitaxial growth and finally a chemical vapour deposition (CVD) step. This in situ cleaning is often accomplished through an H 2 bake at elevated temperature (T4850 1C), which is very effective in removing the remaining contaminants [11,13].…”