Featured Research

from universities, journals, and other organizations

Crystal Growth Yields More Precise Semiconductors

Date:
November 22, 2001
Source:
University Of Wisconsin, Madison
Summary:
Sliced into almost paper-thin discs called wafers, semiconductors hold the circuitry that receives, transmits and processes information. Traditionally, scientists "grow" quantities of single-crystalline semiconducting materials by immersing the tip of a pencil-shaped starter crystal, or "seed," in a melt of the same composition. UW-Madison Materials Science and Engineering Professor Sindo Kou and graduate student Jia-Jie He have devised a method to ensure the melt composition stays constant.

Sliced into almost paper-thin discs called wafers, semiconductors hold the circuitry that receives, transmits and processes information.

Traditionally, scientists "grow" quantities of single-crystalline semiconducting materials by immersing the tip of a pencil-shaped starter crystal, or "seed," in a melt of the same composition. They then slowly withdraw and rotate the seed to form a thick rod shape. To make the crystal develop certain desired properties, they add special impurities to the melt before crystal growth.

However, as the crystal grows, it rejects those impurities into the melt or takes them in. As a result, the melt composition can change during growth - and since the crystal grows from the melt, the crystal composition can continue to change.

When the process is finished, the resulting crystal's composition and properties can vary along its length, so many parts built upon wafers from one crystal can be inconsistent in performance.

UW-Madison Materials Science and Engineering Professor Sindo Kou and graduate student Jia-Jie He have devised a method to ensure the melt composition stays constant.

They first lengthened the crucible in which the materials melt. Then they added a low-temperature heater around the crucible's lower half and moved the existing high-temperature heater to the upper half. The bottom of the crucible holds a solid material identical in composition to the desired crystal; the upper part holds the melt.

As the crystal grows and the melt level decreases, an existing mechanism pushes the crucible upward so that the solid material gradually enters the high-temperature heat zone, melts and keeps the melt composition constant.

Scientists can apply this method to crystals that are a mixture (an alloy) of two different semiconductors and grow them with a uniform composition. With a few modifications, users can adapt this technology easily to their existing equipment. Kou and He are patenting their discovery through the Wisconsin Alumni Research Foundation.


Story Source:

The above story is based on materials provided by University Of Wisconsin, Madison. Note: Materials may be edited for content and length.


Cite This Page:

University Of Wisconsin, Madison. "Crystal Growth Yields More Precise Semiconductors." ScienceDaily. ScienceDaily, 22 November 2001. <www.sciencedaily.com/releases/2001/11/011120052318.htm>.
University Of Wisconsin, Madison. (2001, November 22). Crystal Growth Yields More Precise Semiconductors. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2001/11/011120052318.htm
University Of Wisconsin, Madison. "Crystal Growth Yields More Precise Semiconductors." ScienceDaily. www.sciencedaily.com/releases/2001/11/011120052318.htm (accessed July 31, 2014).

Share This




More Matter & Energy News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
Amid Drought, UCLA Sees Only Water

Amid Drought, UCLA Sees Only Water

AP (July 30, 2014) A ruptured 93-year-old water main left the UCLA campus awash in 8 million gallons of water in the middle of California's worst drought in decades. (July 30) Video provided by AP
Powered by NewsLook.com
Smartphone Powered Paper Plane Debuts at Airshow

Smartphone Powered Paper Plane Debuts at Airshow

AP (July 30, 2014) Smartphone powered paper airplane that was popular on crowdfunding website KickStarter makes its debut at Wisconsin airshow (July 30) Video provided by AP
Powered by NewsLook.com
U.K. To Allow Driverless Cars On Public Roads

U.K. To Allow Driverless Cars On Public Roads

Newsy (July 30, 2014) Driverless cars could soon become a staple on U.K. city streets, as they're set to be introduced to a few cities in 2015. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins