Automatic Resistivity Meter
The original, low cost automatic four point probe.
Easy to operate, simply load the wafer and close the lid.
Automatic calculation and display of sheet or slice resistivity, V/I metallization thickness and P-N type.
Ideal for epitaxial, diffused, ion implanted and metallized layers
Internal self calibration at each measurement ensures instrument accuracy of 0.5%.
The FPP-5000 4-Point Probe simplifies the measurement of resistive properties of semiconductor wafers and resistive films. The microprocessor based electronics permits direct computation of V/I, sheet or slice resistivity, metallization thickness and P-N type testing. The electronics and probing mechanism is contained in a single compact package. The rugged cast aluminum housing assures mechanical integrity of the probe mechanism. The probing mechanism features a constant force probe head which is rigidly fixed in the housing. Unlike most four point probes and probing stations, which move the probe head into the wafer, the FPP-5000 is designed so that the wafer is moved into the probe head. This insures constant probe force independent of operator force and wafer thickness.
An indexing wafer holder allows repeatable probe positioning. Plug in probe heads simplify the changing of probe heads. Electromagnetic interference on high resistivity materials is minimized by an integral cover which is electrically grounded to the chassis. A measurement is automatically made each time the wafer is lowered onto the probe tips. Additional measurements can be made without lifting the cover by depressing the RETEST button. A normal (or forward) and reverse current measurement is made each time a measurement is made. This results in an automatic indication, through an error code, if the probe head is out of adjustment or is excessively worn. Questionable or invalid tests are also indicated by error code displays.
The input amplifier is automatically calibrated for each measurement insuring an accuracy of +/- 0.5% from 5.0 milliohm to 5k ohm. The test current is continuously variable to minimize test current and maximize signal level. The slice or layer thickness necessary to compute the slice resistivity is entered via keyboard switches in microns, mils or Angstroms. The thickness of the layer is entered. The FPP-5000 also can compute the sheet resistivity, compensated for probe tip variations and edge effects for thin semiconductor layers, particularly those formed during ion implantation.
The FPP-5000 automatically performs a semiconductor type test if selected. First a rectification test is performed followed by a thermal type test if necessary. If the results are inconclusive the N and P indicators are simultaneously displayed. If desired, the unit will supply a short low-energy, high-voltage pulse to the probe tips in order to penetrate any thin insulating layer on the sample. Both penetration and typing tests are performed, if activated by front panel switches. However, the penetration tests can be disabled internally (or externally) if inadvertent application would be detrimental to the substrate under test.
· Compact integral probe and display
· Microprocessor based electronics
· Automatic ranging
Four selectable displays
- Sheet Resistivity
- Bulk resistivity of a slice with a known thickness
- Thickness in, A, MILS, or microns of a slice or layer with a known bulk resistivity
· Keyboard Programming of slice or layer thickness or bulk resistivity
· Automatically performs a reverse and forward measurement each time the cover is closed
· RETEST button allows additional measurements without disturbing the probes· Automatically holds the last reading after the probe is released and until the next measurement is made
· Error code displays indicate improper operation, readings and electronics
· Extended measurement range displays sheet resistivity up to 450k ohm/sq and down to
a resolution of .001 milliohm/SQ
· High accuracy of 0.5% of reading on all reading between 5 milliohm to 5 k ohm. No more
than +/- 8.0% at the extreme limits of the range
· Self test circuitry built in to determine if a fault is present
· Self calibration and zero circuitry assures high accuracy in all but extreme ranges
· Index substrate holder allows repeatable probe positioning on the substrate
· Probe up permits repeatable measurements independent of operator force and substrate thickness
· Integral RFI and light shielding for high resistivity measurements
· Plug in probe head adaptors make probe head changing convenient and non critical
· Typing mode determines N and P typing for most semiconductor substrates or layers
· Penetration permits high energy pulse to be applied for the purpose of breaking through thin oxide layers
· Penetrate function can be disabled by means of internal switches
· Automatic calculation of correction factors to compensate for probe tip spacing variations
· Back lit front panel indicates only the units applicable for the mode of operation chosen.
The FPP-5000 requires an input power of 115/230 VAC +/- 10%, 50/60 Hz, at approximately 30 watts.
Based on the 2 configuration technique. Displays if calculated geometric correction is between 4.18 and 4.82.
Calculated values above and below results in a flashing display in display SHEET, SLICE, and THICK.
If as a result of the calculation, the intermediate results are negative, the display will indicate E 07.
Optional RS-232C Interface:
Output on 25 pin female subminiature "D" connector.
Selectable Baud Rate: 9600, 4800, 2400, 1200, 300, 150
Optional Hand Held Probe Head: For testing wafers over 6" in Diameter. Comes with six foot cable. Specify probe head when ordering.