1. Field of the Invention
The invention generally relates to a method of manufacturing fin-type field effect transistors (FinFETs) that allows the length of the FinFET fins to be increased by angling the fins with respect to the gate conductors and prevents the angled fins from increasing the size of the FinFET array by increasing the density of the fins.
2. Description of the Related Art
A fin-type field effect transistor “FinFET” is a type of transistor that has a fin covered by a gate conductor. The gate conductor covers the channel portion of the fin and source and drain portions of the fin extend beyond the coverage of the gate conductor. FinFETs are discussed at length in U.S. Pat. No. 6,413,802 to Hu et al. (hereinafter “Hu”), which is incorporated herein by reference.
As Very Large Scale Integration (VLSI) drives the reduction of the size of transistors to smaller dimensions, the power supply voltage is no longer able to be reduced in proportion due to non-scaling threshold voltages of transistors. This limits the amount of size reduction that can be accomplished on the gate length of FETs, and FinFETs. The invention described below addresses these issues by increasing the effective length of the gate of the FinFET without increasing the size of the transistor array. This allows the size of the transistors to be reduced without reducing the effective length of the gates, thereby allowing the size of the transistor array to be continually decreased.