Patent ID: 6995428
Filing Date: 2006-02-07
Classification: H01L

Abstract:
1. A transistor comprising: a P-substrate; a first diffusion region and a second diffusion region formed in said P-substrate; wherein said first diffusion region and said second diffusion containing N conductivity-type ions form an N-well in said P-substrate; wherein said first diffusion region comprises an extended drain region; a drain diffusion region containing N+ conductivity-type ions, forming a drain region in said extended drain region; a third diffusion region containing P conductivity-type ions, comprising a P-field and divided P-fields formed in said extended drain region; a fourth diffusion region containing P conductivity-type ions, forming an isolated P-well in said N-well formed by said second diffusion region for preventing N-well's breakdown; a source diffusion region having N+ conductivity-type ions, forming a source region in said N-well formed by said second diffusion region; a channel, formed between said source region and said drain region; a thin gate oxide layer, formed over said channel; a polysilicon gate electrode, formed over said channel to control a current flow in said channel; a contact diffusion region containing P+ conductivity-type ions, forming a contact region in said N-well formed by said second diffusion region; a thick field oxide, formed laterally adjacent to said thin gate oxide layer; a drain-gap, formed between said drain diffusion region and said thick field oxide to maintain a space between said drain diffusion region and said thick field oxide; a source-gap, formed between said thick field oxide and said isolated P-well to maintain a space between said thick field oxide and said isolated P-well; an insulation layer, covering said polysilicon gate electrode and said thick field oxide; a drain metal contact, having a first metal electrode for contacting with said drain diffusion region; and a source metal contact, having a second metal electrode for contacting with said source diffusion region and said contact diffusion region; wherein a left edge of the first diffusion region touches a right edge of the fourth diffusion region, said divided P-fields are located nearer to said drain region compared to said P-field, and said P-field and said divided P-fields generate junction fields.