A method and apparatus for estimating a height of an epitaxially grown semiconductor material in other semiconductor devices. The method includes epitaxially growing first, second, and third portions of semiconductor material on a first semiconductor device, measuring a height of the third portion of semiconductor material and a height of the first or second portion of semiconductor material, measuring a first saturation current through the first and second portions of semiconductor material, measuring a second saturation current through the first and third portions of semiconductor material, and preparing a model of the first saturation current relative to the height of the first or second portion of semiconductor material and the second saturation current relative to an average of the height of the first and third portions of semiconductor material. The model is used to estimate the height of an epitaxially grown semiconductor material in the other semiconductor devices.