Wafers need to be inspected at many stages throughout the manufacturing process. Particles and defects need to be detected and classified. Features need to be measured in both the x, y and z direction (critical dimensions and film thickness, for example). Film stoichiometry needs to be measured. Wafer warpage and bow must be evaluated and compensated for. Film stress (either tensile or compressive) is another important measurand as is dopant concentration, adhesion, and dozens if not hundred of other parameters. Variations across the wafer, within each die and die-to-die are also important.

Wafer inspection — also called metrology — is mostly used for process control, to make sure processes are not drifting out of control, As such, measurements are made after each process step — or more infrequently if at all possible since there is a cost associated with every inspection step in terms of capital equipment required, reduced throughput and added particles from increased handling.

Of course, more advanced characterization techniques are also needed for process development and failure analysis.

New inspection challenges include the need to measure more complex device structures such as those found in FinFETs and 3D NAND. The industry is also pushing a wide array of new materials into production, which brings a new set of challenges since each type of material has unique properties when it comes to reflection, refraction, adhesion, stress, etc.

The push to smaller dimensions and thinner films means smaller defects and variations become more important, which often pushes the accuracy, resolution and repeatability limits of today’s measurement tools.

The most common type of wafer inspection tool is the optical microscope. Although still used today for macro inspection, the very small dimension on today’s wafers can only be measured by more advanced means, most notably the scanning electron microscope and the transmission electron microscope. Other commonly used tools include ellipsometers to measure film thickness.

For failure analysis, even more sophisticated surface analysis tools are required, including  ESCA, Auger, EDAX, and Rutherford Backscattering (RBS), among many others.


Eastern Applied Research, Inc.: www.easternapplied.com
Product announcements:

Akrometrix, LLC: www.akrometrix.com

Al Shultz Technology Advertising: http://www.alshultz.com/

Berliner Glas KGaA Herbert Kubatz GmbH & Co.: http://www.berlinerglas.com

Cascade Microtech: http://www.cascademicrotech.com

HEIDENHAIN CORPORATION: http://www.heidenhain.com

Microtronic, Inc.: http://www.microtronic.com

NanoFocus AG: www.nanofocus.com

Prior Scientific, Inc.: http://www.prior.com/

Rudolph Technologies, Inc.: http://www.rudolphtech.com

Semitracks, Inc.: http://www.semitracks.com

TSI Inc. : http://www.tsi.com/

Wright Williams & Kelly, Inc.: http://wwk.com


New laser-based sample prep solution

07/12/2018  3D-Micromac AG (booth #1645 in the South Hall) this week introduced the microPREP 2.0 laser ablation system for high-volume sample preparation of metals, semiconductors, ceramics and compound materials for microstructure diagnostics and failure analysis (FA).

Subfab data growing in importance

07/11/2018  The importance of data gathered and analysed in the subfab – the place where vacuum pumps, abatements systems and other supporting equipment operates – is growing. Increasingly, manufacturers are finding that these systems have a direct impact on yield, safety, cost-of-ownership and ultimately capacity and cycle time.

3D-Micromac introduces selective laser annealing system for semiconductor and MEMS manufacturing

06/25/2018  microPRO RTP leverages optics, line scan and step-and-repeat spot options, and multiple wavelengths to provide highly versatile laser platform.

Kinetics acquires Mega Fluid Systems

03/30/2018  According to the details of the agreement, Mega Fluid Systems will operate as a Kinetics company, but will maintain its brand and product line.

Understanding ALD, MLD and SAMs as they enter the fab

03/01/2018  As the world of advanced manufacturing enters the sub-nanometer scale era, it is clear that ALD, MLD and SAM represent viable options for delivering the required few-atoms-thick layers required with uniformity, conformality, and purity.

US demand for semiconductor machinery to total $7.4B in 2021

02/16/2018  Growth in demand for wafer processing equipment will account for the majority of value growth.

CSTIC and SEMICON CHINA 2018: Brooks Instrument to present new mass flow controller with self-diagnostics​

02/09/2018  Brooks Instrument will showcase its newly enhanced GF125 mass flow controller (MFC) with high-speed EtherCAT connectivity and embedded self-diagnostics at the China Semiconductor Technology International Conference (CSTIC) in conjunction with SEMICON China 2018 in Shanghai.

Leak check semiconductor process chambers quickly and reliably

02/08/2018  INFICON,a manufacturer of leak test equipment, introduced the UL3000 Fab leak detector for semiconductor manufacturing maintenance teams to easily check the tightness of vacuum chambers for wafer production.

Boston Semi Equipment develops custom automation modules for strip handling equipment

01/31/2018  Boston Semi Equipment (BSE) today announced that it has started shipping units of its new strip load/unload module to a top 10 semiconductor manufacturer.

Turbulent times ahead for trade

01/25/2018  International trade is one of the best tools to spur growth and create high-skill and high-paying jobs. Over 40 million American jobs rely on trade, and this is particularly true in the semiconductor supply chain. Over the past three decades, the semiconductor industry has averaged nearly double-digit growth rates in revenue and, by 2030, the semiconductor supply chain is forecast to reach $1 trillion.

NAURA Akrion Inc. acquired Akrion’s surface preparation business

01/18/2018  Beijing NAURA Microelectronics Equipment Co.,Ltd. and Akrion Systems LLC today jointly announced that the previously announced acquisition by NAURA has been completed.

$55.9B semiconductor equipment forecast: New record with Korea at top

12/12/2017  Today, SEMI, the global industry association representing the electronics manufacturing supply chain, released its Year-end Forecast at the annual SEMICON Japan exposition.