Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Semiconductor devices: Under mounting stress

09.11.2012
The recently developed ability to measure physical changes in silicon when processed into microelectronic devices could improve fabrication techniques for even smaller circuits

Thinner semiconductor wafers to house electronic circuits are needed so that more computing power can be packed into ever-smaller electrical products.

Thinning, however, makes the wafers brittle and prone to warping or breaking. A technique for measuring the stress in those chips during production is now available1, thanks to developmental work led by Xiaowu Zhang at the A*STAR Institute of Microelectronics, Singapore. The resulting information could enable miniature but robust semiconductor devices.

The conversion from bare wafer to useful device can be an arduous one for a sheet of silicon, particularly when it is only a few millimeters thick. Fabrication processes can involve bombarding the wafer with a beam of ions, dipping it in corrosive acids to etch tiny structures, exposing it to plasmas for cleaning, or coating it in layers of hot metal to create electrical contacts. Then, the wafer must be fixed into a package.

Zhang and his co-workers designed and built stress sensors directly onto a silicon wafer to monitor the strain that such packaging exerts. They took advantage of the piezoresistive effect in silicon — when a force is applied to a silicon wafer, it pushes atoms closer together. In turn, the change in atom distribution alters the way an electrical current passes through the material, which can be measured as a change in resistance. Each stress sensor consisted of 16 resistors (see image). Since the piezoresistive properties of silicon are well known, Zhang and his co-workers could simply convert the changes in resistance to a corresponding change in stress.

By equally distributing 17 such sensors on the sample surface, the researchers monitored the stress in a silicon wafer during a number of common packaging processes. These included coating the wafer in a thin film and attaching a small bump of solder. They also embedded the sensors into a plastic test board, which they dropped repeatedly. Zhang and co-workers also developed a data acquisition system that could monitor the stresses during this impact test.

“Semiconductors are a multibillion-dollar industry,” explains Zhang. “This stress data should enable the design of novel packaging technologies and reduce the chance of device damage during processing and during daily use and accidents, such as dropping the device.”

Evaluating the stresses on a device wafer during other processes, including a technique known as ‘through-silicon via’, in which electrical connections are passed all the way through the wafer, will be the next step in the team’s research, says Zhang.

The A*STAR-affiliated researchers contributing to this research are from the Institute of Microelectronics.
Associated links
http://www.research.a-star.edu.sg/research/6580
Journal information
Zhang, X., Rajoo, R., Selvanayagam, C. S., Kumar, A., Rao, V. S. et al. Application of piezoresistive stress sensor in wafer bumping and drop impact test of embedded ultrathin device. IEEE Transactions on Components, Packaging and Manufacturing Technology 2, 935–943 (2012).

A*STAR Research | Research asia research news
Further information:
http://www.research.a-star.edu.sg/research/6580
http://www.researchsea.com

More articles from Power and Electrical Engineering:

nachricht Engineers program tiny robots to move, think like insects
15.12.2017 | Cornell University

nachricht Electromagnetic water cloak eliminates drag and wake
12.12.2017 | Duke University

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Error-free into the Quantum Computer Age

A study carried out by an international team of researchers and published in the journal Physical Review X shows that ion-trap technologies available today are suitable for building large-scale quantum computers. The scientists introduce trapped-ion quantum error correction protocols that detect and correct processing errors.

In order to reach their full potential, today’s quantum computer prototypes have to meet specific criteria: First, they have to be made bigger, which means...

Im Focus: Search for planets with Carmenes successful

German and Spanish researchers plan, build and use modern spectrograph

Since 2016, German and Spanish researchers, among them scientists from the University of Göttingen, have been hunting for exoplanets with the “Carmenes”...

Im Focus: Immunsystem - Blutplättchen können mehr als bislang bekannt

LMU-Mediziner zeigen eine wichtige Funktion von Blutplättchen auf: Sie bewegen sich aktiv und interagieren mit Erregern.

Die aktive Rolle von Blutplättchen bei der Immunabwehr wurde bislang unterschätzt: Sie übernehmen mehr Funktionen als bekannt war. Das zeigt eine Studie von...

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Nanostrukturen steuern Wärmetransport: Bayreuther Forscher entdecken Verfahren zur Wärmeregulierung

Der Forschergruppe von Prof. Dr. Markus Retsch an der Universität Bayreuth ist es erstmals gelungen, die von der Temperatur abhängige Wärmeleitfähigkeit mit Hilfe von polymeren Materialien präzise zu steuern. In der Zeitschrift Science Advances werden diese fortschrittlichen, zunächst für Laboruntersuchungen hergestellten Funktionsmaterialien beschrieben. Die hiermit gewonnenen Erkenntnisse sind von großer Relevanz für die Entwicklung neuer Konzepte zur Wärmedämmung.

Von Schmetterlingsflügeln zu neuen Funktionsmaterialien

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

Call for Contributions: Tagung „Lehren und Lernen mit digitalen Medien“

15.12.2017 | Veranstaltungen

Die Stadt der Zukunft nachhaltig(er) gestalten: inter 3 stellt Projekte auf Konferenz vor

15.12.2017 | Veranstaltungen

Mit allen Sinnen! - Sensoren im Automobil

14.12.2017 | Veranstaltungen

 
VideoLinks
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Alexa und Co in unserem Kopf: Wo die Stimmerkennung im Gehirn sitzt

18.12.2017 | Biowissenschaften Chemie

Chemiker der Uni Graz nutzen Treibhausgas zur Herstellung eines Wirkstoffs gegen Schlafkrankheit

18.12.2017 | Biowissenschaften Chemie

Zusammenarbeit von Fraunhofer und Universität in Würzburg bringt Medizinforschung voran

18.12.2017 | Biowissenschaften Chemie