VQ Oxide Monitoring - Overview and Solutions Offered for Monitoring Oxides Using VQ Measurement Technology by Semilab

Semilab designs, produces and sells metrology equipment for the characterization of semiconductor and photovoltaic materials, for monitoring the manufacturing process of semiconductor devices and solar cells, and also for R&D purposes in these areas. Semilab offers a variety of measurement techniques; most of them are non-contact and non-destructive. Many of Semilab's technologies can be flexibly integrated in different platforms, ranging from simple handheld devices and table-top systems with high resolution mapping capability to fully automated stand-alone production control tools for mid-range and high-level fablines. Semilab also offers in-line measurements for solar cell production lines.

Metallic Contamination in Semiconductors

Metallic contamination in semiconductors adversely affects device performance. As linewidths decrease the allowable levels of metal contamination get smaller and smaller. The most commonly occuring forms of metal contamination are either in the middle of the periodic table, called heavy metals, or are in the alkaline metal column, at the left of the periodic table.

Heavy metals diffuse into the bulk silicon. This type of contamination is discussed in the contamination section of this website. Alkaline metal contamination, such as sodium, usually occurs during processing and does not diffuse into the bulk silicon. Alkaline metal contamination affects oxides. The charge of ionized alkaline metals in oxides affects the oxide charge, measured as flat band voltage or equivalent.

Often, it is desirable to separate charge due to mobile ions from charge due to other things in the oxide. Sodium is the most commonly occurring alkaline metal contaminant, and its small diameter, ionized atoms migrate through the oxide in response to bias voltage. This variation in embedded charge in an oxide changes device performance, and the specs become unstable. Thus, it is desirable to limit the mobile charge contamination in an oxide.. Mobile charge can be detected via bias temperature stress tests.

Semilab's Solutions for VQ Oxide Monitoring

The WT-2000 and WT-2500 tools monitor oxides via VQ measurement technology.

Features of Semilab's WT-2000 and WT-2500 for VQ Oxide Monitoring

The features of Semilab's equipments for VQ Oxide monitoring are noted below:

  • High throughput: complete analysis within 15 min
  • High speed, high resolution mapping of a number of parameters
  • Mobile charge measurement capability
  • Combination with bulk contamination measurement such as Laser-SPV/m-PCD
  • Real non-destructive characteristic by neutralizing the wafer after measurements

WT-2000

WT-2000

WT-2500

WT-2500

This information has been sourced, reviewed and adapted from materials provided by Semilab Semiconductor Physics Laboratory.

For more information on this source, please visit Semilab Semiconductor Physics Laboratory.

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