HONG KONG, Dec 13 (Reuters) - China is working on a more than 1 trillion yuan ($143 billion) support package for its semiconductor industry, three sources said, in a major step towards self sufficiency in chips and to counter U.S. moves aimed at slowing its technological advances.Beijing plans to roll out what will be one of its biggest fiscal incentive packages, allocated over five years, mainly as subsidies and tax credits to bolster semiconductor production and research activities at home, said the sources.And U.S. President Joe Biden in August signed a landmark bill to provide $52.7 billion in grants for U.S. semiconductor production and research as well as tax credit for chip plants estimated to be worth $24 billion.With the incentive package, Beijing aims to step up support for Chinese chip firms to build, expand or modernise domestic facilities for fabrication, assembly, packaging, and research and development, the sources said.Achieving self-reliance in technology featured prominently in President Xi Jinping's full work report at the Communist Party Congress in October."