Process corners

About: Process corners is a research topic. Over the lifetime, 912 publications have been published within this topic receiving 9116 citations.

Integrated circuit that supports and method for wafer-level testing

Abstract: An integrated circuit is formed on a die that is formed as a detachable part of a semiconductor wafer. The wafer includes both a wafer test-mode path that is operable to carry a wafer test-mode signal and a wafer power-supply path that is operable to carry a wafer power-supply signal. The integrated circuit includes functional circuitry that supports normal and wafer-test modes of operation and that is coupled to the wafer test-mode path before the die is detached from the wafer. The functional circuitry is operable to function in the wafer test mode of operation when the wafer test-mode signal has a first state. The integrated circuit also includes a wafer test-mode power circuit that is coupled to the functional circuitry, and that is coupled to the wafer power-supply path and the wafer test-mode path before the die is detached from the wafer. The power circuit is operable to couple the wafer power-supply path to the functional circuitry when the wafer test-mode signal has the first state. When the wafer test-mode signal has a second state, the wafer test-mode power circuit is operable to uncouple the wafer power-supply path from the functional circuitry, and the functional circuitry is operable to function in the normal mode of operation.

A Self-Tuning IoT Processor Using Leakage-Ratio Measurement for Energy-Optimal Operation

Abstract: Energy-optimal operation is one of the key requirements of the Internet-of-Things (IoT) applications to increase battery life. In this article, using a combination of dynamic voltage scaling (DVS) and adaptive body biasing (ABB), the energy-optimal operation is achieved with a given fixed operating frequency determined by application demands. Based on the observation that the ratio of leakage power to dynamic power can be an accurate indicator for the optimal operating point, the proposed method dynamically tracks the minimum energy operating points by adjusting supply voltage and body bias with very low hardware and power overhead. A custom dc–dc converter for supply voltage regulation and charge pumps for body bias generation were implemented with the proposed method in a Cortex-M0 processor. Since SRAM is included in the same energy optimization loop as the processor, a custom SRAM was designed to match the processor speed. The design is fabricated in an Mie Fujitsu Semiconductor (MIFS) 55-nm deeply depleted channel (DDC) CMOS and the proposed approach achieves energy consumption within 4.6% of optimal at 1 MHz across five process corners and temperatures from −20 °C to 125 °C. The fabricated processor achieves 6.4 pJ/cycle at 0.55-V and 500-kHz clock frequency.

CMOS Mixed-Signal Circuit Process Variation Sensitivity Characterization for Yield Improvement

Abstract: A mixed-signal circuit?s performance and yield dependency on process variation are investigated with numerical circuit solution, statistical simulation, and implemented circuit measurement in 65nm partially-depleted silicon-on-insulator CMOS process. Increased relative variation in 65nm process is examined with site-to-site and wafer-to-wafer process variations. A current-controlled oscillator?s performance and device threshold voltages are cross-correlated using simulation and RF measurement. Up to 93.9% cross-correlation between oscillation frequency and device threshold voltage is obtained, and strong model-to-hardware correlation is observed through statistical analysis of simulation result and circuit measurement. The yield learning process of design, simulation, measurement, and statistical analysis is proposed.

Method for forming integrated circuits using high aspect ratio vias through a semiconductor wafer

Abstract: An integrated circuit and method for forming the same. The integrated circuit includes a semiconductor wafer with first and second surfaces. A functional circuit is formed on the first surface of the semiconductor wafer. Further, a metallization layer is formed outwardly from the first surface of the semiconductor wafer. The integrated circuit also includes at least one high aspect ratio via that extends through the layer of semiconductor material. This via provides a connection between a lead and the functional circuit.

Spatial estimation of wafer measurement parameters using Gaussian process models

Abstract: In the course of semiconductor manufacturing, various e-test measurements (also known as inline or kerf measurements) are collected to monitor the health-of-line and to make wafer scrap decisions preceding final test. These measurements are typically sampled spatially across the surface of the wafer from between-die scribe line sites, and include a variety of measurements that characterize the wafer's position in the process distribution. However, these measurements are often only used for wafer-level characterization by process and test teams, as the sampling can be quite sparse across the surface of the wafer. In this work, we introduce a novel methodology for extrapolating sparsely sampled e-test measurements to every die location on a wafer using Gaussian process models. Moreover, we introduce radial variation modeling to address variation along the wafer center-to-edge radius. The proposed methodology permits process and test engineers to examine e-test measurement outcomes at the die level, and makes no assumptions about wafer-to-wafer similarity or stationarity of process statistics over time. Using high volume manufacturing (HVM) data from industry, we demonstrate highly accurate cross-wafer spatial predictions of e-test measurements on more than 8,000 wafers.