Qimonda Richmond and Qimonda North America filed their petitions for bankruptcy protection in US bankruptcy court in Delaware, saying they intend to locate a buyer.
Qimonda North America listed assets in excess of $1 billion (Dh3.6bn) and liabilities in excess of $1bn.
Qimonda AG filed for insolvency in January in Germany as a result of huge industry price drops and a global financing squeeze, but said it hoped to continue operations.
Based in Munich, Germany, the company is the world’s fourth-biggest maker of Dram memory chips, used mainly in PCs.
It announced earlier this month that it would shut down its US plant.
Qimonda AG, is a majority-owned subsidiary of Infineon Technologies AG, which owns 77.5 per cent of the company.
Qimonda’s insolvency administrator in Europe has said it needs to find an investor by the end of March to continue operations and avoid liquidation.
Qimonda Richmond said in its bankruptcy filing that prices for Dram products fell sharply in 2007 and steepened their fall again in 2008. The company had tried to diversify its products and, in October 2008, shut down part of its Richmond plant, laying off more than 1,000 workers.
Earlier this month, the Richmond facility was forced to shut down because Qimonda AG was no longer purchasing output from the plant and it had little access to cash and could no longer fund ongoing operations.