An integrated electronic circuit includes a semiconductor substrate with a semiconductor well that is isolated by a buried semiconductor region located under the semiconductor well. A vertical MOS transistor formed in the semiconductor well includes a source-drain region provided by the buried semiconductor region. Backside thinning of the semiconductor substrate is detected by biasing the vertical MOS transistor into an on condition to supply a current and then comparing that current to a threshold. Current less than a threshold is indicative that the semiconductor substrate has been thinned from the backside.