Multi-finger transistor layout for reducing cross-finger electric variations and for fully utilizing available breakdown voltages

摘要

Structure and methods for a semiconductor transistor design. The transistor structure comprises a field effect transistor having a multi-finger gate and three or more diffusion regions. Each diffusion region is identified as either a source region or a drain region, and each diffusion region is further identified as either an inner diffusion region or an outer diffusion region. Electrical contacts are established in the inner diffusion regions and the outer diffusion regions. There are approximately twice as many contacts in an inner source region as in the outer source region. There are approximately twice as many contacts in an inner drain region as in the outer drain region. The number and locations of contacts in each diffusion region are adjusted to reduce the difference among source node voltages of all fingers and the difference among drain node voltages of all fingers.

主权项

1. A method for creating a semiconductor transistor design comprising a field effect transistor having a multi-finger gate structure on a diffusion shape, said multi-finger gate structure comprising gate fingers, and said diffusion shape comprising a diffusion edge positioned along a periphery of said diffusion shape, said method comprising:
identifying, using a computerized device, inner diffusion regions of said multi-finger gate structure as being between said gate fingers; identifying, using said computerized device, outer diffusion regions of said multi-finger gate structure as being one of:
between one of said gate fingers and said diffusion edge; andbetween one of said gate fingers and a dummy finger, said dummy finger being parallel to and electrically disconnected from said gate fingers; identifying, using said computerized device, each of said inner diffusion regions as being one of inner source regions and inner drain regions; identifying, using said computerized device, each of said outer diffusion regions as being one of outer source regions and outer drain regions; establishing electrical contacts in said inner diffusion regions and said outer diffusion regions, said establishing of said electrical contacts complying with a first ratio of there being approximately twice as many of said electrical contacts in said inner source regions as in said outer source regions, and said establishing of said electrical contacts complying with a second ratio of there being approximately twice as many of said electrical contacts in said inner drain regions as in said outer drain regions; tuning said first ratio to cause a voltage drop across said electrical contacts in said inner source regions and across said electrical contacts in said outer source regions to be approximately equal for all said gate fingers; and tuning said second ratio to cause a voltage drop across said electrical contacts in said inner drain regions and across said electrical contacts in said outer drain regions to be approximately equal for all said gate fingers.