Tin oxide films are used as mandrels in semiconductor device manufacturing. In one implementation the process starts by providing a substrate having a plurality of protruding tin oxide features (mandrels) residing on an exposed etch stop layer. Next, a conformal layer of spacer material is formed both on the horizontal surfaces and on the sidewalls of the mandrels. The spacer material is then removed from the horizontal surfaces exposing the tin oxide material of the mandrels, without fully removing the spacer material residing at the sidewalls of the mandrel (e.g., leaving at least 50%, such as at least 90% of initial height at the sidewall). Next, mandrels are selectively removed (e.g., using hydrogen-based etch chemistry), while leaving the spacer material that resided at the sidewalls of the mandrels. The resulting spacers can be used for patterning the etch stop layer and underlying layers.

Tin oxide film on a semiconductor substrate is etched selectively in a presence of silicon (Si), carbon (C), or a carbon-containing material (e.g., photoresist) by exposing the substrate to a process gas comprising hydrogen (H.sub.2) and a hydrocarbon. The hydrocarbon significantly improves the etch selectivity. In some embodiments an apparatus for processing a semiconductor substrate includes a process chamber configured for housing the semiconductor substrate and a controller having program instructions on a non-transitory medium for causing selective etching of a tin oxide layer on a substrate in a presence of silicon, carbon, or a carbon-containing material by exposing the substrate to a plasma formed in a process gas that includes H.sub.2 and a hydrocarbon.

Tin oxide film on a semiconductor substrate is etched selectively in a presence of silicon (Si), carbon (C), or a carbon-containing material (e.g., photoresist) by exposing the substrate to a process gas comprising hydrogen (H.sub.2) and a hydrocarbon. The hydrocarbon significantly improves the etch selectivity. In some embodiments an apparatus for processing a semiconductor substrate includes a process chamber configured for housing the semiconductor substrate and a controller having program instructions on a non-transitory medium for causing selective etching of a tin oxide layer on a substrate in a presence of silicon, carbon, or a carbon-containing material by exposing the substrate to a plasma formed in a process gas that includes H.sub.2 and a hydrocarbon.

A semiconductor resist composition includes an organometallic compound represented by Chemical Formula 1 and a solvent: ##STR00001##
wherein, in Chemical Formula 1, R.sup.1 is an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or an -alkyl-O-alkyl group, and R.sup.2 to R.sup.4 are each independently selected from —OR.sup.a and —OC(═O)R.sup.b. The semiconductor resist composition may have excellent solubility and storage stability.

A semiconductor resist composition includes an organometallic compound represented by Chemical Formula 1 and a solvent: ##STR00001##
wherein, in Chemical Formula 1, R.sup.1 is an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or an -alkyl-O-alkyl group, and R.sup.2 to R.sup.4 are each independently selected from —OR.sup.a and —OC(═O)R.sup.b. The semiconductor resist composition may have excellent solubility and storage stability.

A method includes forming a dummy gate structure over a substrate; forming a plurality of gate spacers on opposite sidewalls of the dummy gate structure; forming an interlayer dielectric (ILD) layer surrounding the gate spacers; replacing the dummy gate structure with a metal gate structure; etching back the metal gate structure to form a gate trench between the gate spacers; depositing a first dielectric layer in the gate trench, in which the first dielectric layer has horizontal portions over the metal gate structure and the ILD layer, and vertical portions on sidewalls of the gate spacers; etching the vertical portions of the first dielectric layer until the sidewalls of the gate spacers exposed; and performing depositing the first dielectric layer and etching the vertical portions of the first dielectric layer in an alternate manner.

A method includes forming a dummy gate structure over a substrate; forming a plurality of gate spacers on opposite sidewalls of the dummy gate structure; forming an interlayer dielectric (ILD) layer surrounding the gate spacers; replacing the dummy gate structure with a metal gate structure; etching back the metal gate structure to form a gate trench between the gate spacers; depositing a first dielectric layer in the gate trench, in which the first dielectric layer has horizontal portions over the metal gate structure and the ILD layer, and vertical portions on sidewalls of the gate spacers; etching the vertical portions of the first dielectric layer until the sidewalls of the gate spacers exposed; and performing depositing the first dielectric layer and etching the vertical portions of the first dielectric layer in an alternate manner.

First to third insulators are successively formed in this order over a first conductor over a semiconductor substrate; a hard mask with a first opening is formed thereover; a resist mask with a second opening is formed thereover; a third opening is formed in the third insulator; a fourth opening is formed in the second insulator; the resist mask is removed; a fifth opening is formed in the first to third insulators; a second conductor is formed to cover an inner wall and a bottom surface of the fifth opening; a third conductor is formed thereover; polishing treatment is performed so that the hard mask is removed, and that levels of top surfaces of the second and third conductors and the third insulator are substantially equal to each other; and an oxide semiconductor is formed thereover. The second insulator is less permeable to hydrogen than the first and third insulators, the second conductor is less permeable to hydrogen than the third conductor.

First to third insulators are successively formed in this order over a first conductor over a semiconductor substrate; a hard mask with a first opening is formed thereover; a resist mask with a second opening is formed thereover; a third opening is formed in the third insulator; a fourth opening is formed in the second insulator; the resist mask is removed; a fifth opening is formed in the first to third insulators; a second conductor is formed to cover an inner wall and a bottom surface of the fifth opening; a third conductor is formed thereover; polishing treatment is performed so that the hard mask is removed, and that levels of top surfaces of the second and third conductors and the third insulator are substantially equal to each other; and an oxide semiconductor is formed thereover. The second insulator is less permeable to hydrogen than the first and third insulators, the second conductor is less permeable to hydrogen than the third conductor.

Tin oxide films are used as spacers and hardmasks in semiconductor device manufacturing. In one method, tin oxide layer (e.g., spacer footing) needs to be selectively etched in a presence of an exposed silicon-containing layer, such as SiOC, SiON, SiONC, amorphous silicon, SiC, or SiN. In order to reduce damage to the silicon-containing layer the process involves passivating the silicon-containing layer towards a tin oxide etch chemistry, etching the tin oxide, and repeating passivation and etch in an alternating fashion. For example, passivation and etch can be each performed between 2-50 times. In one implementation, passivation is performed by treating the substrate with an oxygen-containing reactant, activated in a plasma, and the tin oxide etching is performed by a chlorine-based chemistry, such as using a mixture of Cl.sub.2 and BCl.sub.3.