Shares of Applied Materials fell sharply Friday after the company lowered its current-quarter revenue and sales projections in its semiconductor business below Wall Street expectations.

Applied Materials, which makes equipment used to produce chips, saw its stock fall more than 9.5 percent Friday morning, on track for its worst day since February 2009.

As one of the globe’s largest supplier of tools used by chipmakers, the company’s disappointing forecast only fueled investor anxiety that a plateauing smartphone market could finally curb demand for flash memory chips.

“Smartphone sales have been below expectations, particularly for high-end models. And in response, both semiconductor and display suppliers have made adjustments to their capacity planning,” chief executive Gary Dickerson told investors on Thursday’s earnings call.

Applied Materials said it expects semiconductor sales revenue to grow 7 percent in the current quarter, well short of the 13.8 percent boost expected by the Street, according to FactSet.