摘要:
In one aspect, the present disclosure encompasses polymerization systems for the copolymerization of CO2 and epoxides comprising 1) a catalyst including a metal coordination compound having a permanent ligand set and at least one ligand that is a polymerization initiator, and 2) a chain transfer agent having two or more sites that can initiate polymerization. In a second aspect, the present disclosure encompasses methods for the synthesis of polycarbonate polyols using the inventive polymerization systems. In a third aspect, the present disclosure encompasses polycarbonate polyol compositions characterized in that the polymer chains have a high percentage of —OH end groups and a high percentage of carbonate linkages. The compositions are further characterized in that they contain polymer chains having an embedded polyfunctional moiety linked to a plurality of individual polycarbonate chains.
摘要:
The disclosure pertains to amphiphilic block copolymers comprising an aliphatic polycarbonate chain coupled to a hydrophilic polymer. Such amphiphilic polymers may have the formula A-L-B, where A- is a polycarbonate or polyethercarbonate chain having from about 3 to about 500 repeating units, L is a linker moiety and —B is a hydrophilic oligomer having from about 4 to about 200 repeating units. Provided copolymers are useful as surfactants capable of emulsifying aqueous solutions and supercritical carbon dioxide. Provided copolymers also have utility as additives for use in enhanced oil recovery methods.
摘要:
Dual stress liners for CMOS applications are provided. The dual stress liners can be formed from silicon nitride having a first portion for inducing a first stress and a second portion for inducing a second stress. An interface between the first and second stress portions is self-aligned and co-planar. To produce a co-planar self-aligned interface, polishing, for example, mechanical chemical polishing is used.
摘要:
(Salph or methoxy salph) Co (initiating ligand) catalyze homopolymerizing rac-PO to produce pure highly isotactic PPO and rac-1-butylene oxide to produce pure isotactic poly(butylene oxide). A product is unfractionated isotactic PPO of m-dyad content >81%, normally at least 99%.
摘要:
An opto-thermal annealing method for forming a field effect transistor uses a reflective metal gate so that electrical properties of the metal gate and also interface between the metal gate and a gate dielectric are not compromised when opto-thermal annealing a source/drain region adjacent the metal gate. Another opto-thermal annealing method may be used for simultaneously opto-thermally annealing: (1) a silicon layer and a silicide forming metal layer to form a fully silicided gate; and (2) a source/drain region to form an annealed source/drain region. An additional opto-thermal annealing method may use a thermal insulator layer in conjunction with a thermal absorber layer to selectively opto-thermally anneal a silicon layer and a silicide forming metal layer to form a fully silicide gate.
摘要:
An opto-thermal annealing method for forming a field effect transistor uses a reflective metal gate so that electrical properties of the metal gate and also interface between the metal gate and a gate dielectric are not compromised when opto-thermal annealing a source/drain region adjacent the metal gate. Another opto-thermal annealing method may be used for simultaneously opto-thermally annealing: (1) a silicon layer and a silicide forming metal layer to form a fully silicided gate; and (2) a source/drain region to form an annealed source/drain region. An additional opto-thermal annealing method may use a thermal insulator layer in conjunction with a thermal absorber layer to selectively opto-thermally anneal a silicon layer and a silicide forming metal layer to form a fully silicide gate.
摘要:
(Salph or methoxy salph) Co (initiating ligand) catalyze homopolymerizing rac-PO to produce pure highly isotactic PPO and rac-1-butylene oxide to produce pure isotactic poly(butylene oxide). A product is unfractionated isotactic PPO of m-dyad content >81%, normally at least 99%.
摘要:
The embodiments of the invention generally relate to an etching process, and more particularly to an etch processing for improving the yield of dielectric contacts on nickel silicides. An oxygen-free feedgas is used in an etching process to reduce or eliminate residuals, including oxidation and consumption of the silicide layer, at the contact surface. The contact resistance at contact surface is reduced, thereby improving the performance of the device.
摘要:
In one aspect, the present invention provides catalysts for the carbonylation of heterocycles. The inventive catalysts feature metal-ligand complexes having cationic functional groups tethered to the ligand, wherein the tethered cationic groups are associated with anionic metal carbonyl species. The invention also provides methods of using the inventive catalysts to affect the ring opening carbonylation of epoxides.