It would be advantageous to be able to provide a device that amplifies a current in response to a control current in some CMOS devices. For example, current-mode sense amplifiers for use in reading-out memory cells have faster read times than voltage-based devices. Unfortunately, conventional CMOS fabrication techniques are not well-adapted for fabricating current-to-current gain devices such as bipolar junction transistors. Normal CMOS processing does not provide full junction isolation of the type needed to construct bipolar junction transistors. Hence, to construct such transistors in CMOS, 3 to 5 additional masking steps and additional implant/diffusion steps are required. This increases the cost of the devices and requires larger die sizes.
Broadly, it is the object of the present invention to provide an improved CMOS transistor design.
It is a further object of the present invention to provide a CMOS device that controls a current in response to another current.
It is yet another object of the present invention to provide a CMOS device that mimics the behavior of a bipolar junction transistor.
These and other objects of the present invention will become apparent to those skilled in the art from the following detailed description of the invention and the accompanying drawings.