Abstract:
Method for forming three-dimensional device structures such as a trench capacitor DRAM cell comprising a second device (370) formed over a first device (315) is disclosed. A layer (350,355) having a single crystalline top surface (350) is formed above the first device (315) to provide the base for forming the active area of the second device.
Abstract:
Methods for forming or etching silicon trench isolation (STI) in a silicon-on-insulator (SOI) region and a bulk silicon region, and a semiconductor device so formed, are disclosed. The STI can be etched simultaneously in the SOI and bulk silicon regions by etching to an uppermost silicon layer using an STI mask, conducting a timed etch that etches to a desired depth in the bulk silicon region and stops on a buried insulator of the SOI region, and etching through the buried insulator of the SOI region. The buried insulator etch for this process can be done with little complexity as part of a hardmask removal step. Further, by choosing the same depth for both the bulk and SOI regions, problems with a subsequent CMP process are avoided. The invention also cleans up the boundary between the SOI and bulk regions where silicon nitride residuals may exist.
Abstract:
In integrated circuits having copper interconnect and low-k interlayer dielectrics, a problem of open circuits after heat treatment was discovered and solved by the use of a first liner layer (42) of Ti, followed by a conformal liner layer (46) of CVD TiN, followed in turn by a final liner layer (48) of TA or TaN, thus improving adhesion between the via and the underlying copper layer while reducing the increase in resistance caused by alloying between the Ti and the copper to an acceptable amount.
Abstract:
A simplified method of fabricating a storage node for a deep trench-based DRAM on a semiconductor substrate. The method involves the etching a trench in a surface of the substrate and then forming a layer of dielectric material on a sidewall of the trench the top portion of which is subsequently removed from the sidewall. Next, a layer of oxide is grown on the exposed portion of the sidewall. A portion of this layer of oxide is then removed from the sidewall in order to orient the layer of oxide a predetermined distance from the surface of the substrate. Finally, the trench is filled with a semiconductive material.