GaAs/AlGaAs self-sensing cantilevers for low temperature scanning probe microscopy

We have fabricated scanning probe microscope cantilevers with dimensions 65×11.4×0.25 μm3 and 3×2×0.129 μm3 from GaAs/Al0.3Ga0.7As heterostructures containing two-dimensional electron gases. Deflection is measured by an integrated field-effect transistor (FET) that senses strain via the piezoelectric effect and provides a low noise, low power displacement readout. We present images of a 200 nm mica grating taken with the large cantilever having a deflection (force) noise 10 A/√Hz (19 pN/√Hz) at T=2.2 K. The small cantilever has a resonant frequency of 11 MHz, a FET gate charge noise of 0.001 e/√Hz, and is projected to have a deflection (force) noise of 0.002 A/√Hz (1 pN/√Hz) at T=4.2 K.

[1]  Gus Gurley,et al.  Short cantilevers for atomic force microscopy , 1996 .

[2]  N. D. Rooij,et al.  Microlever with combined integrated sensor/actuator functions for scanning force microscopy , 1994 .

[3]  C. Quate,et al.  Atomic resolution with an atomic force microscope using piezoresistive detection , 1993 .

[4]  Shunji Watanabe,et al.  Micro‐fabricated piezoelectric cantilever for atomic force microscopy , 1996 .

[5]  R. Westervelt,et al.  CRYOGENIC SCANNING PROBE CHARACTERIZATION OF SEMICONDUCTOR NANOSTRUCTURES , 1996 .

[6]  M. Roukes,et al.  Fabrication of high frequency nanometer scale mechanical resonators from bulk Si crystals , 1996 .

[7]  J. E. Stern,et al.  Force microscope using a fiber‐optic displacement sensor , 1988 .

[8]  K. Fricke.  Piezoelectric properties of GaAs for application in stress transducers , 1991 .

[9]  Michael L. Roukes,et al.  Direct thermal conductance measurements on suspended monocrystalline nanostructures , 1997 .

[10]  Michel Devoret,et al.  Single Charge Tunneling , 1992 .

[11]  R. Westervelt,et al.  Strain‐sensing cryogenic field‐effect transistor for integrated strain detection in GaAs/AlGaAs microelectromechanical systems , 1996 .

[12]  J. Tansock,et al.  Force measurement with a piezoelectric cantilever in a scanning force microscope , 1992 .

[13]  A. Fung,et al.  Linear in-plane uniaxial stress effects on the device characteristics of AlGaAs/GaAs modulation doped field effect transistors , 1997 .

[14]  Tadatomo Suga,et al.  Scanning force microscope using a piezoelectric microcantilever , 1994 .