ASTM_F_42_-_93_1997.pdf

Designation:F 42 93(Reapproved 1997)DIN 50432Standard Test Methods forConductivity Type of Extrinsic Semiconducting Materials1This standard is issued under the fixed designation F 42;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 These test methods2cover the determination of theconductivity type of extrinsic semiconductors.While explicitdetails are given for germanium and silicon,inclusion of otherextrinsic materials such as gallium arsenide and indium anti-monide should be feasible.For the latter compounds,however,applicability has not been formally verified by round-robintests.Determinations can be made most reliably on homoge-neous bulk material,but these test methods may also be used tomap regions of different conductivity type on the surfaces ofinhomogeneous specimens.These test methods have not beentested on layered structures such as epitaxial layers.Measure-ments on these structures may give erroneous indications ofconductivity type.1.2 Four test methods are described:1.2.1 TestMethodAHot-ProbeThermalEMFConductivity-Type Test.1.2.2 TestMethodBCold-ProbeThermalEMFConductivity-Type Test.1.2.3 TestMethodCPoint-ContactRectificationConductivity-Type Test.1.2.4 Test Method DType-All3system operating in twomodes:1.2.4.1Rectification Conductivity-Type Test.1.2.4.2Thermal EMF Conductivity-Type Test.1.3 Experience has shown that Test Method A(hot-probe)gives dependable results in n-and p-type silicon having aroom-temperature resistivity up to 1000 Vcm.NOTE1Resistivity of germanium specimens may be measured inaccordance with Test Methods F 43 and resistivity of silicon slices may bemeasured in accordance with Test Methods F 43 or Test Method F 84.1.4 Test Method B(cold-probe)gives dependable results forn-and p-type germanium having a room-temperature resistiv-ity of 20 Vcm or less and for n-and p-type silicon having aresistivity up to 1000 Vcm(Note 1).This technique has theadvantage over the hot-probe test method in that the signalamplitude can be increased by developing a greater tempera-ture difference between the two probes.1.5 Test Method C(rectification)is a simple convenienttechnique which gives dependable results for n-and p-typesilicon with room-temperature resistivity between 1 and 1000Vcm.This test method is not recommended for germanium(Note 1).1.6 Test Method D(type-all rectification mode)is appropri-ate for use on n-and p-type silicon having a room-temperatureresistivity between 0.1 and 1000 Vcm,inclusive(Note 1).1.7 Test Method D(type-all thermal emf mode)is appro-priate for use on n-and p-type silicon having a room-temperature resistivity between 0.002 and 0.1 Vcm,inclusive(Note 1).1.8 These test methods may apply outside the limits givenabove,but their suitability outside these limits has not beenverified experimentally.1.9 It is recommended that if satisfactory results can not beobtained with the use of these test methods that conductivitytype be determined from Hall-effect measurements as de-scribed in Test Methods F 76.NOTE2DIN 50432 covers technical equivalents to Test Methods Aand C of these test methods,but does not include Test Methods B and D.1.10 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:D 1125 Test Methods for Electrical Conductivity and Re-sistivity of Water4F 43 Test Methods for Resistivity of Semiconductor Mate-rials5F 76 Test Methods for Measuring Resistivity and HallCoefficient and Determining Hall Mobility in Single-Crystal Semiconductors51These test methods are under the jurisdiction of ASTM Committee F-1 onElectronics,and are the direct responsibility of Subcommittee F01.06 on SiliconMaterials and Process Control.Current edition approved Aug.15,1993.Published October 1993.Originallypublished as F 42 64 T.Last previous edition F 42 88.2DIN 50432 is an equivalent method.It is the responsibility of DIN CommitteeNMP 221,with which Committee F-1 maintains close technical liaison.DIN 50432,Testing of Inorganic Semiconductor Materials:Determining theConductivity Type of Silicon or Germanium by Means of the Rectification Test orHot Probe,is available from Beuth Verlag GmbH,Burggrafenstrasse 4-10,D-1000Berlin 30,Federal Republic of Germany.3Keenan,W.A.,Schneider,C.P.,and Pillus,C.A.,“Type-All System forDetermining Semiconductor Conductivity Type,”Solid State Technology,Vol 14,No.3,March 1971.4Annual Book of ASTM Standards,Vol 11.01.5Annual Book of ASTM Standards,Vol 10.05.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Rep