Abstract: Sequential processes are conducted in a batch reaction chamber to form ultra high quality silicon-containing compound layers, e.g., silicon nitride layers, at low temperatures. Under reaction rate limited conditions, a silicon layer is deposited on a substrate using trisilane as the silicon precursor. Trisilane flow is interrupted. A silicon nitride layer is then formed by nitriding the silicon layer with nitrogen radicals, such as by pulsing the plasma power (remote or in situ) on after a trisilane step. The nitrogen radical supply is stopped. Optionally non-activated ammonia is also supplied, continuously or intermittently. If desired, the process is repeated for greater thickness, purging the reactor after each trisilane and silicon compounding step to avoid gas phase reactions, with each cycle producing about 5-7 angstroms of silicon nitride.

Abstract: Thin films are formed by formed by atomic layer deposition, whereby the composition of the film can be varied from monolayer to monolayer during cycles including alternating pulses of self-limiting chemistries. In the illustrated embodiments, varying amounts of impurity sources are introduced during the cyclical process. A graded gate dielectric is thereby provided, even for extremely thin layers. The gate dielectric as thin as 2 nm can be varied from pure silicon oxide to oxynitride to silicon nitride. Similarly, the gate dielectric can be varied from aluminum oxide to mixtures of aluminum oxide and a higher dielectric material (e.g., ZrO2) to pure high k material and back to aluminum oxide. In another embodiment, metal nitride (e.g., WN) is first formed as a barrier for lining dual damascene trenches and vias. During the alternating deposition process, copper can be introduced, e.g.