A step-wise process is disclosed for the efficient deposition of silicon. The process begins by reacting trichlorosilane and hydrogen on a heated substrate to deposit silicon. Silicon deposition efficiency of this reaction is determined by measuring the silicon to chlorine ratio in the deposition reaction effluent. The silicon-bearing effluent from the deposition reaction includes trichlorosilane, dichlorosilane, and silicon tetrachloride. The silicon-bearing effluent is collected in a first accumulator. The deposition reaction is continued using the collected quantity of silicon-bearing effluent together with an additional quantity of trichlorosilane as an input to the continuing reaction. The additional quantity of trichlorosilane is determined to make up the amount of silicon deposited in the previous step. The process is step-wise continued by measuring the silicon to chlorine ratio in the deposition reactor effluent, collecting an additional quantity of silicon-bearing effluent in a second accumulator, and using this silicon bearing effluent together with an additional quantity of trichlorosilane as an input to the reaction. In each step the ratio of silicon to chlorine in the deposition reactor effluent is measured and the amount of additional makeup trichlorosilane added to the recycled silicon bearing effluent is determined to supply a constant rate of silicon as input to the reaction. The step-wise reaction continues until steady state equilibrium is achieved.
Polysilicon dendrites are grown by depositing silicon on a polysilicon rod or other substrate. Surface temperature is increased to a temperature at which needle-like dendrites develop due to the deposition of silicon from silicon-containing molecules in the surrounding reactor atmosphere. Thereafter, the surface temperature is gradually reduced so that silicon that deposits on the needle-like dendrites causes the dendrites to grow and assume a generally flared shape.
5698261 - Process for producing silicon carbide layers and an article - Owned by Aktsionernoe Obschestvo Russkoe Obschestvo Prikladnoi Elektroniki (Moscow,RU) Mitin; Vladimir Vasilievich (Moscow,RU) Chernikov; Georgy Evgenievich (Nizhnevartovsk,RU) Ivanov; Leonard Stepanovich (Moskow,RU)
A process for depositing silicon carbide layers to produce highly pure silicon carbide having a stoichiometric composition and a theoretical density includes feeding a gas mixture to a heated substrate under specified conditions, separating the decomposition products into gas and liquid phases by condensation, rectifying the liquid phase and recycling recovered materials, cooling the gas phase and recovering a solid deposit, and compressing and recycling hydrogen.
The invention discloses an SiO.sub.2--TiO.sub.2 glass, which is preferably made by flame-hydrolysis and which distinguishes itself by increased resistance to radiation, especially in connection with EUV lithography. By purposefully reducing the hydrogen content, clearly improved resistance to radiation and reduced shrinking is achieved.
A method and apparatus for continuously reacting a feed gas to form a product and separating the product from unreacted feed gas is provided. The apparatus includes a plurality of compartments and means for connecting the compartments in a series, with the last compartment in the series being connected to the first compartment in the series to provide a closed loop. Each compartment may include an upstream reaction zone and a downstream separation zone.
A method and apparatus for continuously reacting a feed gas to form a product and separating the product from unreacted feed gas is provided. The apparatus includes a plurality of compartments and means for connecting the compartments in a series, with the last compartment in the series being connected to the first compartment in the series to provide a closed loop. Each compartment may include an upstream reaction zone and a downstream separation zone.
