Low dielectric constant group II-VI compounds, such as zinc oxide, and fabrication methods are disclosed. Low dielectric constant insulator materials are fabricated by doping zinc oxide with at least one mole % p-type dopant ion. Low dielectric constant zinc oxide insulator materials are fabricated by doping zinc oxide with silicon having a concentration of at least 10.sup.17 atoms/cm.sup.3. Low dielectric zinc oxide insulator materials are fabricated by doping zinc oxide with a dopant ion having a concentration of at least about 10.sup.18 atoms/cm.sup.3, followed by heating to a temperature which converts the zinc oxide to an insulator. The temperature varies depending upon the choice of dopant. For arsenic, the temperature is at least about 450.degree. C.; for antimony, the temperature is at least about 650.degree. C. The dielectric constant of zinc oxide semiconductor is lowered by doping zinc oxide with a dopant ion at a concentration at least about 10.sup.18 to about 10.sup.19 atoms/cm.sup.3.