Abstract: Methods of forming trench-based isolation regions with reduced susceptibility to edge defects include the steps of forming trenches at a face of a semiconductor substrate and then filling the trenches with electrically insulating regions. However, to prevent exposure of those portions of the substrate extending adjacent the trenches, supplemental oxide regions are formed at the interfaces between the upper portions of the trench sidewalls and the electrically insulating regions in the trenches, by exposing the electrically insulating regions to an oxidation atmosphere at a temperature in a range between about 950.degree. C. and 1100.degree. C. In particular, the supplemental oxide regions are formed as thermal oxides of higher density than the electrically insulating regions in the trenches. Thus, the supplemental oxide regions are more resistant to chemical etchants.

Abstract: A device isolation trench is formed in a semiconductor substrate by forming spaced apart masking regions on the substrate, leaving an exposed portion of the substrate disposed therebetween. A masking layer is formed on the masking regions and the exposed portion of the substrate. The masking layer and the substrate are then anisotropically etched for an etching time sufficient to remove the masking layer and portions of the substrate disposed between the masking regions and thereby form a device isolation trench in the substrate having rounded edges. Preferably, the step of anisotropically etching includes etching with an etchant that etches the substrate and the masking layer at approximately the same etching rate. More preferably, the substrate is silicon and the masking layer is polysilicon or amorphous silicon. The masking layer may also be high-thermal oxide (HTO) having an etching rate lower than that of the substrate.

Abstract: A method for forming a microelectronic structure includes the steps of forming a mask layer on a substrate, forming a trench in the exposed portion of the substrate, forming a layer of an insulating material which fills the trench and covers the mask layer, and annealing the insulating material at a temperature of at least about 1,150.degree. C. The annealing step can be performed for a period of time of about .5 hours to about 8 hours, and the annealing step can be performed in an inert atmosphere.

Abstract: A device isolation method divides a semiconductor substrate into active and inactive regions. A first device isolation layer is formed in a first inactive region using a trench isolation method. Then, local oxidation is used to form a second device isolation layer in a second inactive region which is wider than the first. A dishing phenomenon (generated during CMP processing) is eliminated, and proper device isolation is realized without exposing the active region.

Abstract: A method for efficiently removing by-products produced in dry-etching a fabricated structure of a semiconductor device, particularly, a polycide structure. The method includes the steps of sequentially forming a polysilicon layer and a refractory metal silicide layer to overlie previously fabricated structures on a semiconductor substrate, dry-etching the polysilicon layer and the refractory metal silicide layer to form a patterned polysilicon layer and a patterned refractory metal silicide layer, and thermal treating the resultant structure to remove at least one kind of by-product produced in the dry-etching step at a temperature higher than the boiling point of any by-product.