The material of the present invention is prepared by repeated application of a two-step process. In a formation step, a sub-coalescent amount of a non-single crystalline silicon material is formed. A sub-coalescent amount is an amount of material that is insufficient to provide full coverage of the surface upon which it is formed. Instead, portions of the surface upon which formation occurs remain uncovered and growth of the ultimate semiconductor body does not occur in a layer-by-layer fashion. The sub-coalescent structures that are formed in the formation step contain a high fraction of surface atoms and possess a distorted bonding configuration. The formation step can be accomplished by a variety of methods including physical vapor deposition, chemical vapor deposition, plasma-enhanced chemical vapor deposition, laser ablation sputtering, and evaporation. Representative suitable reactants for this step include SiH.sub.4, Si.sub.2 H.sub.6 and related silicon compounds either undiluted or diluted with H.sub.2. The purpose of the formation step is to provide sub-coalescent structures that will subsequently be stabilized and incorporated into the body of the ultimate semiconductor to be prepared.
In the treatment step, the sub-coalescent structures formed in the formation step are treated with a plasma comprised of hydrogen, fluorine, argon, nitrogen, oxygen or a combination thereof in a suitable reaction chamber. The purpose of the second step is to terminate the coordinatively unsaturated surface atoms of the sub-coalescent structures to produce and stabilize coordinatively irregular structures that are characterized by a state of structural order, coordination properties and chemical bonding that are distinct from those of the amorphous and crystalline phases with the same composition.
Hmm, this is new - the process is different from the method we discussed a while ago where H2 dilution control was used to try to stay at the amorphous-microcrystalline phase boundary.
No device results, so it is difficult to evaluate if it works.
They are trying to get the Ge out of the bottom cell which is a good thing. Germane is expensive and toxic and the least amount of O2 incorporation in the layer makes it a dead device. |
