Steven D. Golladay

EBM-9000: EB mask writer for product mask fabrication of 16nm half-pitch generation and beyond

EBM-9000 equipped with new features such as new electron optics, high current density (800A/cm2) and high speed deflection control has been developed for the 11nm technology node(tn) (half pitch (hp) 16nm). Also in parallel of aggressive introduction of new technologies, EBM-9000 inherits the 50kV variable shaped electron beam / vector scan architecture, continuous stage motion and VSB-12 data format handling from the preceding EBM series to maintain high reliability accepted by many customers. This paper will report our technical challenges and results obtained through the development.

A voltage contrast detector for electrical testing of multi-chip substrates

Abstract A voltage contrast detector successfully applied to high speed opens/shorts testing of 90 × 90 mm multi-chip substrates is described. In contrast to the chip testing environment where beam induced charging is primarily a problem to be avoided, beam induced charging is fundamental to the substrate test method. As such the charging process must be well controlled, both in terms of the potential to which conductors are charged and the degree to which charging is confined to the intended conductor. The role of the detector in both aspects of charging control is described.

New electron optics for mask writer EBM-7000 to challenge hp 32nm generation

Semiconductor scaling is expected to continue to hp32nm and beyond, accompanied by explosive data volume expansion. Required minimum feature size at hp 32nm will be less than 50nm on the mask, according to ITRS2007(1). EBM 7000 is a newly designed mask writer for the hp32 nm node with an improved electron optical column providing the beam resolution (10 nm measured in situ) and beam current density (200 A/cm2) necessary for cost effective mask production at hp32nm node. In this paper we report on column improvements, the in situ beam blur measurement method and writing results from EBM 7000. Written patterns show dose margin (CD change [nm] / 1 % dose change) of .94 nm /1 % dose for line/space arrays using chemically amplified resist PRL009 and our standard processing. Using a simple model to relate the measured beam intensity distribution to the measured dose margin, we infer an effective total blur of 30 nm, dominated by a contribution of 28 nm from the resist exposure and development process. Further evidence of the dominance of the process contribution is the measured improvement in dose margin to .64 nm/% dose obtained by modifying our standard process. Even larger process improvements will be needed for successful fabrication of hp22nm masks.

PREVAIL - Latest electron optics results

The PREVAIL electron optics subsystem developed by IBM has been installed at Nikons facility in Kumagaya, Japan, for integration into the Nikon commercial EPL stepper. The cornerstone of the electron optics design is the Curvilinear Variable Axis Lens (CVAL) technique originally demonstrated with a proof of concept system. This paper presents the latest experimental results obtained with the electron optical subsystem at Nikons facility. The results include micrographs illustrating proper CVAL operation through the spatial resolution achieved over the entire optical field of view. They also include data on the most critical issue of the EPL exposure approach: subfield stitching. The methodology of distortion correction will be described and both micrographs and metrology data of stitched subfields will be presented. This paper represents a progress report of the IBM/Nikon alliance activity on EPL.

High speed testing of conductor networks with electron beams

Abstract IBMs experience with the internally developed e-beam system, PL-1, for electrical continuity testing of multi-layer, multi-chip packaging substrates is reviewed. The contactless test methods employed by PL1 are described and the capabilities and limitations of the e-beam tester are compared with those of several different types of mechanical probers. We also describe the architecture and major system features of Pl-1, the results of a study of its performance in finding open and short defects, and recent practical applications.

PREVAIL e-beam stepper alpha tool

PREVAIL is the high throughput e-beam projection approach to NGL, which IBM is pursuing in cooperation with Nikon as alliance partner. Key lithographic building blocks of the technology have been demonstrated experimentally with a proof-of-concept (POC) system and results have been reported earlier at MNE 99 and elsewhere. This paper reports on the implementation of the PREVAIL technology in a production-level e-beam stepper. The architecture and writing strategy of the tool together with design features of the various tool subsystems are described.

PREVAIL: EPL alpha tool electron optics subsystem

The IBM/Nikon alliance is continuing pursuit of an EPL stepper alpha tool based on the PREVAIL technology. This paper provides a status report of the alliance activity with particular focus on the Electron Optical Subsystem developed at IBM. We have previously reported on design features of the PREVAIL alpha system. The new state-of-the-art e-beam lithography concepts have since been reduced to practice and turned into functional building blocks of a production level lithography tool. The electron optical alpha tool subsystem has been designed, build, assembled and tested at IBMs Semiconductor Research and Development Center (SRDC) in East Fishkill, New York. After demonstrating subsystem functionality, the electron optical column and all associated control electronics hardware and software have been shipped during January 2001 to Nikons facility in Kumagaya, Japan, for integration into the Nikon commercial e-beam stepper alpha tool. Early pre-shipment results obtained with this electron optical subsystem are presented.