# Application of Quarter-Wave Transformers for Precise Measurement of Complex Microwave Conductivity of Semiconductors (Short Papers)

TL;DR: The utility of a quarter-wave transformer for precise measurement of complex microwave conductivity of semiconductors has been demonstrated in this paper, where it has been shown that the improvement in measurement accuracy is nearly by a factor of 3 over the conventional reflection measurement using a Teflon transformer.

Abstract: The utility of a quarter-wave transformer for precise measurement of complex microwave conductivity of semiconductors has been demonstrated. It has been shown for a chosen conductivity of 9 /spl Omega//spl dot/cm that the improvement in measurement accuracy is nearly by a factor of 3 over the conventional reflection measurement using a Teflon transformer.

##### Citations

More filters

••

[...]

07 Oct 2003

TL;DR: In this paper, the free-space reflection and transmission coefficients of a silicon wafer sandwiched between two teflon plates which are quarter-wavelength at midband were measured in the frequency range of 11-12.5 GHz.

Abstract: A non-destructive, non-contact technique has been developed to characterize p-type and n-type silicon semiconductor wafers at microwave frequencies. The measurement system consists of a pair of spot-focusing horn lens antennas, mode transitions, coaxial cables and a vector network analyser (VNA). In this paper, the free-space reflection and transmission coefficients, S/sub 11/ and S/sub 21/, for a normally incident plane wave, are measured for a silicon wafer sandwiched between two teflon plates which are quarter-wavelength at midband. The actual reflection and transmission coefficient, S/sub 11/ and S/sub 21/, of the silicon wafers are calculated from the measured S/sub 11/ and S/sub 21/ of the teflon plate-silicon wafer-teflon plate assembly in which the complex permittivity and thickness of the teflon plates are known. From the complex permittivity, the resistivity and conductivity can be obtained. Results are reported in the frequency range of 11-12.5 GHz. The values of the dielectric constant obtained were close to published values for silicon wafers.

8 citations

••

[...]

TL;DR: In this article, a vector network analyzer (VNA), a pair of coaxial cable, coaxial to waveguide adapter and dielectric-filled standard gain horn antenna were used to characterize p-type and n-type silicon semiconductor wafers.

Abstract: A non-destructive and easy to use method is presented to characterize p-type and n-type silicon semiconductor wafers using a rectangular dielectric waveguide measurement (RDWG) system The measurement system consists of a vector network analyzer (VNA), a pair of coaxial cable, coaxial to waveguide adapter and dielectric-filled standard gain horn antenna In this method, the reflection and transmission coefficients, S11 and S21, were measured for silicon wafer sandwiched between the two Teflon, the dielectric that filled the standard gain horn antenna It was observed that, the dielectric constant of the silicon wafers are relatively constant, varying slightly over the frequency range of 9 to 12 GHz The loss factor, loss tangent and conductivity of the doped wafers are higher than the undoped type

7 citations

••

[...]

05 Oct 2004

TL;DR: An algorithm using only transmission measurements to calculate the complex permittivity of p-type and n-type silicon semiconductor wafers using a spot-focused free-space measurement system was developed in this article.

Abstract: An algorithm using only transmission measurements to calculate the complex permittivity of p-type and n-type silicon semiconductor wafers using a spot-focused free-space measurement system was developed The dielectric constant obtained was close to published values for silicon wafers The errors associated with the measurement of the complex permittivity values are discussed, and comparisons between the measured and calculated magnitude and phase of the forward reflection and transmission coefficients are presented In this method, the free-space reflection and transmission coefficients, S/sub 11/ and S/sub 21/, are measured for a silicon wafer sandwiched between two teflon plates which are quarter-wavelength at midband The actual reflection and transmission coefficient, S/sub 11/ and S/sub 21/ of the silicon wafers are then calculated from the measured S/sub 11/ and S/sub 21/ by using ABCD matrix transformation in which the complex permittivity and thickness of the teflon plates are known Results are reported in the frequency range of 8-125 GHz

4 citations

••

[...]

TL;DR: In this paper, an inverted power-law mixing rule model computing volume fractions in which three or more prime materials should be taken to get in the resulting homogeneous mixture the required dielectric properties.

Abstract: Many applications in wireless communication, microelectronics, and microwave power engineering rely on dielectrics with particular dielectric properties. This article proposes an original approach that can be used for producing materials with required complex permittivity. The technique is based on an inverted power-law mixing rule model computing volume fractions in which three or more prime materials should be taken to get in the resulting homogeneous mixture the required dielectric properties. Functionality of the approach is demonstrated by production of composites from a polymer matrix (polymethyl methacrylate) and two inorganic fillers (silicon and alumina). The composites are made by mechanically mixing the powders and axially hot-pressing and cooling the mixture. Complex permittivity of the samples is measured by a split-post resonator method. Experimental data on dielectric properties of the samples help calibrate the technique; for the used powders, the Looyenga power-law model is found to be most adequate. In the produced samples, the target values of dielectric constant are reached with a higher precision than the ones of the loss factor; however, analysis of the production process and error propagation in the computations suggest that deviations of the resultant complex permittivity fall in the anticipated ranges. Features and issues of both computational and production parts of the technique are finally discussed. POLYM. ENG. SCI., 58:319–326, 2018. VC 2017 Society of Plastics Engineers

4 citations

••

[...]

TL;DR: In this paper, a contactless and non-destructive method is presented to characterize p-type and n-type silicon semiconductor wafers using a spot-focused free-space measurement system.

Abstract: A contactless and non-destructive method is presented to characterize p-type and n-type silicon semiconductor wafers using a spot-focused free-space measurement system. In this method, the free-space reflection and transmission coefficients, S 11 and S 21 , are measured for silicon wafer sandwiched between two teflon plates which are quarter-wavelength at mid-band. The actual reflection and transmission coefficient, S 11 and S 21 of the silicon wafers are then calculated from the measured S 11 and S 21 by using ABCD matrix transformation in which the complex permittivity and thickness of the teflon plates are known. Complex permittivity are computed using only the transmission coefficient, S 21 . From the complex permittivity, the resistivity and conductivity can be obtained. Results are reported in the frequency range of 9–12.5 GHz. The dielectric constant obtained were close to published values for silicon wafers and the resistivities agree well with that measured by other conventional method.

3 citations

##### References

More filters

••

[...]

TL;DR: In this paper, an attempt has been made to improve the reflection results from an analysis of the parameters of a circle diagram for reflection coefficient obtained on using a variable reactive termination after the semiconductor-filled waveguide section.

Abstract: Complex microwave conductivity of 9 /spl Omega/ /spl dot/ cm p-type silicon samples has been measured using conventional reflection and transmission bridges to examine their relative advantages and disadvantages. An attempt has been made to improve the reflection results from an analysis of the parameters of a circle diagram for reflection coefficient obtained on using a variable reactive termination after the semiconductor-filled waveguide section. In conformity with the calculated accuracy attainable from different types of measurement under the actual experimental condition, using commercial standards, the dielectric constant for the sample was found to be scattered over a region of /spl plusmn/0.4. It has been concluded that because of lack of accuracy in commercial standards for attenuation and phase shift, the potential accuracy of the conventional microwave methods falls too short of its mark to make any detinite conclusion about the effective mass of carriers in semiconductors at room temperatures.

17 citations

••

[...]

TL;DR: In this article, a calibration procedure is presented which compensates rigorously for the effects introduced by discontinuities due to the end of the slot, and due to possible adaptors, coupling elements, bead supports, etc, and the presence of a slot in creating a guide wavelength and characteristic impedance slightly different from that of a guide without a slot.

Abstract: The basic slotted section measurements of VSWR and the location of the voltage minimum are affected by the variety of errors inherent in the slotted section Considered here are those effects, important for precision measurements, introduced by discontinuities due to the end of the slot, and due to possible adaptors, coupling elements, bead supports, etc, and by the presence of the slot in creating a guide wavelength and characteristic impedance slightly different from that of a guide without a slot A calibration procedure is presented which compensates rigorously for these effects in a simple fashion

11 citations

##### Related Papers (5)

[...]

[...]

[...]