Abstract: A method of fabricating a buried contact in a static random access memory. A gate oxide layer, a first conducting layer and a masking layer are formed sequentially on a substrate. A buried contact opening is formed inside the gate oxide layer, the first conducting layer and the masking layer, which opening exposes a part of the substrate. An epitaxial layer is formed inside the buried contact opening, which epitaxial layer fills up the buried contact opening. After the masking layer is removed, a second conducting layer is formed above the substrate. A buried contact is formed in the substrate that is below the epitaxial layer. The gate oxide layer, the first conducting layer, the epitaxial layer and second conducting layer are patterned to expose a part of the substrate and a part of the buried contact. A source/drain is formed in the substrate and a part of the source/drain is mixed with a part of the buried contact.

Abstract: A method for improving the uniformity of wafer-to-wafer film thicknesses. Before depositing films, shower heads in a PECVD system is heated to production temperature to make the entire system (including the shower heads) reach a stable temperature in coordination with heating of a heater block. Subsequently, a gas source, output via the shower heads, is provided, and then a plasma of the gas source is generated to form a film on the wafer due to the temperatures of the shower heads remain constant during wafers deposition. Therefore, the problem of the uneven thicknesses of films among wafers is resolved. Moreover, if the heating of the shower heads by use of a plasma (which can also be used to heat the heater block) and the heater block is concurrently performed after the preventive maintenance (PM) or open chamber cleaning of the PECVD system, the heating time of the heater block can be further shortened.

Abstract: A method is described for forming a hemispherical grained silicon structure. A patterned amorphous silicon layer is formed over a wafer. The amorphous silicon layer is etched by an etching step with a mixed solution including a hydrofluoric solution and an oxidizing agent. A cleaning step is performed with the hydrofluoric solution. An annealing step is performed to form the hemispherical grained silicon structure.