Selective deposition of amorphous silicon film seeded in a chlorine gas and a hydride gas ambient when forming a stacked capacitor with HSG

A method for forming capacitors in an insulative layer supported by a substrate, the method comprising the steps of:

• forming multiple containers in the insulative layer comprising pillars of doped silicon painted with layers of undoped amorphous silicon;
• removing selected portions of the insulative layer to expose exterior sidewalls of the containers;
• seeding the amorphous silicon layer s of the containers in low-pressure, low temperature environment containing chlorine to prevent silicon formation between containers on the insulative layer;
• and
• annealing the containers at a higher temperature to convert the seeded amorphous layers to HSG.

A method of forming an HSG polysilicon film on silicon structures supported by a substrate and separated by insulative material, comprising:

• forming a thin, amorphous silicon layer on the underlying silicon structures;
• seeding the amorphous silicon layer with a chemical species in combination with a hydride gas flow to form a doped silicon layer on the underlying silicon;
• adding a chlorine-containing gas during seeding to retard any bonding of silicon to the insulative material;
• heating the substrate during seeding to a temperature below the temperature sufficient to permit active formation of HSG on the silicon layer;
• and
• thereafter, vacuum annealing the layer at a higher temperature and for a time duration sufficient so as to convert the doped silicon layer to an HSG polysilicon film on the silicon structure.

A method of forming HSG layers separated by insulative material on a substrate, comprising:

• forming HSG precursor layers of amorphous silicon;
• seeding a chemical species onto the layers of amorphous silicon at a low temperature and low pressure wherein the seeding is performed in the presence of a hydride gas diluted with a chlorine gas which prevents build-up os silicon on the insulative material;
• and
• forming the HSG layers by converting the HSG precursor layers to HSG layers.

A method for forming a capacitor in an insulative layer supported by a substrate, the method comprising the steps of:

• removing a first portion of the insulator layer to form an opening;
• forming a first layer of undoped amorphous silicon on the insulative layer and the opening;
• forming a layer of doped amorphous silicon on the first layer of silicon;
• forming a second layer of undoped amorphous silicon on the doped layer of silicon;
• forming a container in the insulative layer by planarization to remove lateral portions of the first and second layers of undoped amorphous silicon and the layer of doped amorphous silicon;
• removing selected portions of the insulative layer to expose at least a portion of exterior sidewalls of the container which projects from the surface of the insulative layer as a pillar of doped silicon surrounded with layers comprising undoped silicon;
• and
• seeding the first and second amorphous silicon layers in a seeding environment consisting of a carrier gas with a dilute hydride gas and a chemical species at a first temperature and pressure to form a seeded silicon coating on the silicon layers;
• preventing the silicon coating from building up on the insulative layer by adding chlorine to the gases used in the preceding seeding step after stabilization of the hydride flow;
• and
• annealing the seeded amorphous silicon layers at a second temperature which is higher than the first temperature thereby to convert the first and second layers to HSG while continuing the flow of the carrier gas.

A method for forming capacitors in an insulative layer supported by a substrate, the method comprising the steps of:

• forming multiple containers in the insulative layer, each container comprising a pillar of doped silicon sandwiched between with layers of substantially undoped amorphous silicon;
• removing selected portions of the insulative layer to expose exterior sidewalls of the containers;
• seeding the amorphous silicon layers of the containers in a low-pressure, low-temperature environment containing chlorine to prevent silicon formation between containers on the insulative layer;
• and
• annealing the containers at a higher temperature to convert the seeded amorphous layers to HSG.