Super junction trench power MOSFET devices
View Patent ↗In a super junction trench power MOSFET (metal oxide semiconductor field effect transistor) device, a column of p-type dopant in the super junction is separated from a first column of n-type dopant by a first column of oxide and from a second column of n-type dopant by a second column of oxide. In an n-channel device, a gate element for the FET is advantageously situated over the column of p-type dopant; and in a p-channel device, a gate element for the FET is advantageously situated over the column of n-type dopant.
1. A super junction trench power metal oxide semiconductor field effect transistor (MOSFET) device having a channel of first type dopant, said device comprising:
a first column comprising insulating material that separates a column of second type dopant from a first column of said first type dopant;
a second column comprising insulating material that separates said column of said second type dopant from a second column of said first type dopant;
a gate element for a field effect transistor, wherein said gate element is aligned between said first column of insulating material and said second column of insulating material and is positioned above said column of said second type dopant; and
a trench formed between said gate element and an adjacent gate element, said trench extending into said first column of said first type dopant, said trench filled with source metal.
2. The super junction trench power MOSFET device of claim 1 further comprising an isolation layer that separates said gate element from said column of said second type dopant.
3. The super junction trench power MOSFET device of claim 1 wherein said first type dopant comprises n-type dopant and said second type dopant comprises p-type dopant.
4. The super junction trench power MOSFET device of claim 1 further comprising a layer of said source metal that is electrically shorted to said column of said second type dopant.
5. The super junction trench power MOSFET device of claim 4 wherein said layer of source metal is electrically shorted to said column of said second type dopant in a direction that is orthogonal to the longitudinal axis of said column of said second type dopant.
6. The super junction trench power MOSFET device of claim 1 further comprising:
a source region of said first type dopant disposed between said gate element and said trench; and
a body region between said source region and said first column of said first type dopant, wherein said trench extends above and below said source region and is also adjacent said body region.
7. The super junction trench power MOSFET device of claim 1 wherein said trench is aligned with the longitudinal axis of said first column of said first type dopant.
8. The super junction trench power MOSFET device of claim 7 wherein said trench is separated from said first column of said first type dopant by a region of said second type dopant.
9. The super junction trench power MOSFET device of claim 1 wherein said gate element is aligned with the longitudinal axis of said column of said second type dopant.
10. The super junction trench power MOSFET device of claim 1 wherein said first type dopant comprises p-type dopant and said second type dopant comprises n-type dopant.
11. The super junction trench power MOSFET device of claim 1 further comprising a third column of insulating material adjacent said gate element and a fourth column of insulating material adjacent said gate element, wherein said first column of insulating material and said third column of insulating material together provide a continuous boundary that separates said gate element and said column of said second type dopant from said first column of said first type dopant, and wherein said second column of insulating material and said fourth column of insulating material together provide a continuous boundary that separates said gate element and said column of said second type dopant from said second column of said first type dopant.