In this paper, we show the versatility of using molecular-beam epitaxy (MBE) for the growth of the mercury cadmium telluride (HgCdTe) system. Abrupt composition profiles, changes in doping levels or switching doping types are easily performed. It is shown that high-quality material is achieved with Hg(1–x)Cd x Te grown by MBE from a cadmium mole fraction of x = 0.15 to x = 0.72. Doping elements incorporation as low as 1015 cm−3 for both n-type and p-type material as well as high incorporation levels >1018 cm−3 for both carrier types were achieved. X-ray curves, secondary-ion mass spectrometry (SIMS) data, Hall data, the influence of doping incorporation with cadmium content and growth rate, etch pit density (EPD), composition uniformity determined from Fourier-transform infrared (FTIR) transmission spectro-scopy, and surface defect maps from low to high x values are presented to illustrate the versatility and quality of HgCdTe material grown by MBE. All data presented in this work are from layers grown on silicon (112) substrate.

An initial investigation of the use of atomic nitrogen for controlled p-type doping of wide-bandgap Hg0.3Cd0.7Te (x = 0.7) is reported. Mixtures of argon and nitrogen, ranging in nitrogen concentration from 0.1% to 100%, have been utilized to demonstrate well-controlled nitrogen incorporation in the 1016 cm−3 to 1020 cm−3 range using total gas flow rates of 0.3 sccm to 4.0 sccm and radiofrequency (RF) powers of 100 W to 400 W. Nitrogen doping exhibits several desirable attributes including abrupt turn-on and turn-off and minimal sensitivity to variations in growth temperature and HgCdTe composition, with no negative effects on HgCdTe dislocation density and morphology. Preliminary electrical measurements indicate primarily n-type behavior in the 1014 cm−3 to 1015 cm−3 range in as-grown x = 0.7 HgCdTe and CdTe films doped with nitrogen at 1018 cm−3 to 1020 cm−3 concentrations, while ZnTe films have exhibited p-type electrical activity with hole concentrations approaching 1020 cm−3.

We have produced superconducting thin films of Y1Ba2Cu3Ox (YBCO) on SrTiO3, ZrO2(Y2 O3), and Al2O3 having Tc’s of 90 K and sharp ΔTc’s (0.3 K for 90% to 10% on SrTiO3 and 3.3×105 A/cm2 at 78 K). Samples were fabricated in a three target magnetron co‐sputtering, computer controlled system using separate BaF2, Y, and Cu targets. Rutherford backscatterng (RBS) and resistivity measurements showed that the thickness and composition uniformity was 99% across a 2‐in.‐diameter substrate. Films were deposited at room temperature and were subsequently annealed in wet O2 at 850 °C for 1.0 hr. Analysis of the films by x‐ray diffraction indicates highly oriented crystalline structure with a and c axes perpendicular to the substrate surface for (100) SrTiO3, and randomly oriented Y1Ba2Cu3Ox polycrystalline structure for ZrO2 and Al2O3.Both laser ablation and photolithographic/ion milling processes were developed to pattern the high Tc superconducting films. Bridge structures were fabricated in thin films deposited on sapphire and ZrO2 substrates. Weak link Josephson behavior was observed from 4.2 K up to Tc.We have also fabricated single‐element detectors using thin films of superconducting YBaCuO and demonstrated IR sensitivity with responsivities ≂3×103 V/W.