Composition for forming silica layer and silica layer

A composition for forming a silica layer, the composition comprising:

• a silicon-containing polymer;
• and
• a solvent,
• wherein the silicon-containing polymer is an inorganic polysilazane,
• wherein the inorganic polysilazane has a weight average molecular weight of 8,600 g/mol to 13,000 g/mol;
• wherein the solvent is at least one selected from the group consisting of benzene, toluene, xylene, ethylbenzene, diethylbenzene, trimethylbenzene, triethylbenzene, cyclohexane, cyclohexene, decahydronaphthalene, dipentene, pentane, hexane, heptane, octane, nonane, decane, ethylcyclohexane, methylcyclohexane, cyclohexane, cyclohexene, p-menthane, dipropyl ether, dibutyl ether, anisole, butyl acetate, amyl acetate, methyl isobutyl ketone, and a combination thereof, and
• when adding 70 g of the composition to a 100 ml container, sealing the container, leaving the sealed container at 40° C. for 28 days, and then taking a 1 ml sample of gas from the sealed container, the 1 ml sample of the gas comprises hydrogen gas (H2), silane gas (SiH4), and ammonia gas (NH3), and the hydrogen gas, the silane gas, and the ammonia gas satisfy Equation 1:
• (hydrogen gas amount (ppm))/(silane gas amount (ppm)+ammonia gas amount (ppm))≥1.5 [Equation 1].