NRW series
Resistivity Reference Wafer

Selling Points

NRW series are resistivity reference wafers which proven by Napson’s resistivity measurement system. NRW series use wafers with neutron irradiation, and excellent stability.

Napson’s four-probe resistivity measurement system has been calibrated by standard wafers (NIST, VLSI), and conforms to the standards stipulated by the following SEMI standards, Japanese Industrial Standards (JIS) and American Materials Testing Association (ASTM).

〈Compliance standards〉

[SEMI Standards]
SEMI-MF43-99, SEMI-MF374-02, SEMI-MF84-02, SEMI-MF1529-02

[American Society for Testing and Materials]
ASTM-F-84-99(SEMI-MF84), ASTM-F-374-00a, ASTM-F-390-11, ASTM-F-1529-97

[Japan Industrial Standards]



  • 〈Material〉Silicon
  • 〈Production method〉FZ
  • 〈Wafer finish frontside/backside〉Lapped
  • 〈Wafer orientation〉(1-1-1) ± 1 deg.
  • 〈Doping〉N-type (Phosphorous)
  • 〈Wafer size〉Φ100mm(4inch)
  • 〈Wafer Thickness〉*Depends on NRW wafer type. Please refer following specs.


Types Resistivity
Sheet resistance
*calculated value
NRW-1-28 28.00 ±2.00 559.00 ±25.00 Approx. 500
NRW-2-110 110.00 ±11.00 580.00 ±10.00 Approx. 2000
NRW-3-200 200.00 ±12.00 675.00 ±25.00 Approx. 3000
NRW-4-330 330.00 ±25.00 675.00 ±25.00 Approx. 5000
NRW-5-550 550.00 ±50.00 450.00 ±25.00 Approx. 12000

Guaranteed accuracy of Resistivity

Guaranteed position Accuracy
Center area
(*φ5mm spot from sample center)
± 3 %

*Napson’s evaluation criteria conditions / guarantee accuracy under the environment

Product Information

Products Lineups

Measurement principles & methods of Resistance Download by PDF file

*If you want PDF file [Measurement principles & methods of Resistance], please click here.