Logic characterization vehicle to determine process variation impact on yield and performance of digital circuits

Abstract

Manufacturing of integrated circuits relies on the sequence of many hundred process steps. Each of these steps will have more or less variation, wbicb has to be within a certain limit to guarantee the chips functionality at a target speed. But, not every chip layout is susceptive to process variation the same way, wbicb requires a link between process capabilities and product design. This paper will present a novel Logic Characterization Vehicle (LCV) to investigate the yield and performance impact of process variation on high volume product chips. The LCV combines and manipulates new or already documented circuits like memory cells and combinatorial logic circuits within a JIG interface that allows fast and easy testability. Beside the functionality of such circuits, also path delay as well as cross talk issues can be determined. A standard digital functional tester can be used, since all timing critical measurements will be performed within the JIG. The described method allows early implementation of existing circuits for future technology nodes (shrinks). A Design Of Experiments (DOE) based implementation of possible layout manipulations will determine their impact on yield and performance of a target design as well as its sensitivity to process variation. The described approach can be used at a much earlier stage of product and process development, which will significantly shorten yield ramp.

Measuring Power Distribution System Resistance Variations

“…12, except in this case, the computed values are scaled up by a factor of two, to better illustrate their variation around the "average" Rh values displayed in the curves on the far right. The similarity of the 4-port and 6-port curves with the 2-port curves suggests (8) and (9) are better able to represent the resistance characteristics of the PDS. A major portion of the difference that remains in these curves is due to measurement noise, as described in Section V.…”

“…References [8] provide a sample of recent work. The techniques proposed in [8] through [13] make use of ring oscillators and other types of test structures to track variations in front-end-of-line parameters (FEOL) or single wire/via in BEOL parameters. For example, in [8], the authors propose a logic characterization vehicle to investigate the yield and performance impact of process variations.…”

“…The techniques proposed in [8] through [13] make use of ring oscillators and other types of test structures to track variations in front-end-of-line parameters (FEOL) or single wire/via in BEOL parameters. For example, in [8], the authors propose a logic characterization vehicle to investigate the yield and performance impact of process variations. Digitally configured ring oscillators are proposed in [9] to measure of the effects of process variations on performance.…”

Proactive BEOL yield improvement methodology for a successful mobile product

“…Only a small fraction of systematic defects can be expected to be observed using standard in line inspection and metrology tools. In order to find those undetected defects and to determine the root cause, a "Characterization Vehicle" (3) which covers mUltiple design customers and the variation in design rules was designed.…”

Library-based process test vehicle design framework

“…est vehicle or test chip has proven its un-replaceable role in contribution to integrated circuit process development [1]- [7]. A test vehicle used in the purpose of process development contains two major categories: one is the test structure set for process parameter extraction [1], and the other is an IC chip for product qualification evaluation [6].…”