Woun-Suck Yang

Highly manufacturable 4 Gb DRAM using using 0.11 /spl mu/m DRAM technology

4 Gb DRAM has been developed successfully using 0.11 /spl mu/m DRAM technology. Considering manufacturability, we have focused on developing patterning technology that makes 0.11 /spl mu/m design rules possible using KrF lithography. Also, novel DRAM technologies, which have a big influence on the future DRAM integration, are developed as follows:, using novel oxide (SOG) for the enhanced capability of gap-filling, borderless metal contact and stud processes, line-type storage node SAC, thin gate oxide, and CVD Al process for metal interconnections.

A Full FinFET DRAM Core Integration Technology Using a Simple Selective Fin Formation Technique

A full FinFET DRAM core which consists of McFETs for both the sense amplifiers and the sub-word drivers, as well as FinFETs for the memory cell array has been developed. It will efficiently shrink chip size and improve chip performance, and therefore, meet requirements for the future DRAMs with 55nm or smaller design rule. Newly developed schemes which are a selective STT SiN liner removal process, a selective TiN gate stack and narrow active pitch patterning have been successfully integrated

A Novel DRAM Cell Transistor Featuring a Partially-insulated Bulk FinFET (Pi-FinFET) with a pad-Polysilicon Side Contacts (PSC)

The pad-polysilicon side contact (PSC) has drastically improved the performance of the partially-insulated bulk FinFET (Pi-FinFET). PSC enabled to dope a source and drain (S/D) of the fin structure uniformly from the top of the fin to the Pi layer. Since the uniform S/D increases effective channel width, the drivability was increased by 100% compared to the conventional bulk FinFET cell. Nevertheless, hot carrier (HC) lifetime was extended because the position of the highest electric field was nearer to the gate edge compared to the conventional. The total junction leakage current became 50% of the conventional due to the Pi layer. Undoped silicon selective epitaxial growth (SEG) buffered PSC could control gate induced drain leakage (GIDL) to the same level of conventional bulk FinFET. In addition, by optimizing fin height, 25% less word line capacitance (Cwl) was achieved. We place this Pi-FinFET with PSC is one of the promising candidates for the future FinFET DRAM cell technology.

A Novel Multi-Fin DRAM Periphery Transistor Technology using a Spacer Transfer through Gate Polysilicon Technique

Abstract A new technique which integrates the metal gate multi-FinFETs and the conventional polysilicon gate planar FETs is proposed. It solves the problems of conventional scheme, such as complication of process integration due to coexistence of TiN gate FinFETs and polysilicon gate planar FETs, fin width consumption by multi gate oxidation, large fin-pitch limited by lithography and STI gap-filling. A newly proposed technique forms multi-fin structure by spacer transfer process through gate polysilicon electrode of planar FETs. Drain current gain due to increase of effective channel width is estimated and basic electrical characteristics of multi-FinFET are evaluated.