Rotated field effect transistors and method of manufacture

1. A method, comprising:

providing a substrate including at least a first gate structure and a second gate structure, the first gate structure and the second gate structure are not parallel to each other;

performing a first ion implant at a first angle substantially orthogonal to an edge of the first gate structure to form a first impurity region; and

performing a second ion implant at a second angle substantially orthogonal to the first ion implant to form a second impurity region under an edge of the second gate structure,

wherein a linewidth control of the second gate structure is relaxed.

2. A method, comprising:

providing a substrate including at least a first gate structure and a second gate structure, the first gate structure and the second gate structure are not parallel to each other;

performing a first ion implant at a first angle substantially orthogonal to an edge of the first gate structure to form a first impurity region; and

performing a second ion implant at a second angle substantially orthogonal to the first ion implant to form a second impurity region under an edge of the second gate structure, wherein:

the first gate structure includes two or more gates in parallel;

the second gate structure has a channel length longer than a channel length of the first gate structure;

the first gate structure forms a field effect transistor (FET) of a digital device and the second gate structure forms a FET of an analog device;

a linewidth control of the second gate structure is relaxed;

the first impurity region and the second impurity region are different; and

the first and second ion implant are halo and extension implants.