Germanium-film resistance temperature sensors can be used for static and dynamic temperature measurements in the 30 mK to 500 K temperature range.   

wide temperature range for operation (0.03 to 500 K)
monotonic response over a wide temperature range
small temperature reading errors for operation in magnetic fields
small size
extremely fast response to temperature changes
high radiation tolerance
high quality and low price

The thermometers are based on Ge film resistors deposited onto semi-insulating GaAs substrates using vacuum technology. Ge-on-GaAs film temperature sensing elements are produced using standard semiconductor processing techniques and provide high device sensitivity within the range 0.03 K to 500 K. The prepared sensing elements are then employed in different packages.

At present three types of sensor packages are offered:- cylindrical canister package, made from gold plated copper (3 mm in diameter and 5.0 mm long), micro-package (1.2 mm in diameter and 1.0 mm long) and micro-package with plate (2 mm square by 0.15 mm thick).

The micro-thermometers (1.2 mm in diameter and 1.0 mm long) can be used when temperature measurement with high spatial resolution and small response time is required. They may also be incorporated in other packages.

Typical temperature dependences of resistance and sensitivity for different models of thermometers

Overall and detailed views of the thermometer package design

Cylindrical canister package (CP model):- 3.0 mm in diameter and 5.0 mm long

Micro-package (MP model):- 1.2 mm in diameter and 1.0 mm thick

The temperature sensing element is contained within an alumina tube which has copper end caps. The element is bonded to the one of end cap and electrical contact made to both caps through 30-50 µm gold wires. Finally, copper wires are soldered to the end caps to facilitate four-terminal measurements.

The micro-packaged thermometer with plate, MPP model

The micro-packaged thermometer is soldered to the plate (2 mm square by 0.15 mm thick). Electrical contacts made of copper wires, which are soldered to the plate to provide measurements.

L I T E R A T U R E

 
1. ª.Ô.Âåíãåð, À.Ñ.Çåíê³í, Í.Ë.Êîçåëëî, Á.Ï.Êîëîäè÷, Í.Ì.Êðèíèöüêà, Î.Ñ.Êóëèê, Â.Ô.̳ò³í, ².Þ.Íåì³ø, Â.Â.Õîëåâ÷óê. ̳í³àòþðí³ êðåìí³ºâ³ ä³îäí³ òà ãåðìàí³ºâ³ ðåçèñòèâí³ òåðìîìåòðè äëÿ âèì³ðþâàííÿ íèçüêèõ òåìïåðàòóð. Ô³çèêà ³ õ³ì³ÿ òâåðäîãî ò³ëà, 2, 499-505 (2010).

 
2. V.F.Mitin, N.S.Boltovets, V.V.Kholevchuk, V.V.Basanets, E.V.Mitin, P.C.McDonald, F.Pavese. Dual function sensors for concurrent measurements of temperature and magnetic fields in cryogenic applications. Cryogenics, Vol. 48, pp. 413-416 (2008).

 
3. V.F. Mitin, P.C. McDonald, F. Pavese, N.S. Boltovets, V.V. Kholevchuk, I.Yu. Nemish, V.V. Basanets, V.K. Dugaev, P.V. Sorokin, R.V. Konakova, E.F. Venger, E.V. Mitin, Ge-on-GaAs film resistance thermometers for cryogenic applications. Cryogenics, Vol. 47, pp. 474-482 (2007).


Back