Methods of manufacturing semiconductor devices with a deep barrier layer
First Claim
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1. A method of manufacturing a semiconductor device, the method comprising:
- etching a plurality of trenches to a first depth in a semiconductor substrate by forming a structured trench etch hard mask on a first main surface of the semiconductor substrate and etching the plurality of trenches to the first depth in the semiconductor substrate through openings in the structured trench etch hard mask;
doping a region of the semiconductor substrate surrounding a bottom of the trenches at the first depth to form a doped region in the semiconductor substrate;
before the doped region is formed, forming a protection layer or stack of protection layers on sidewalls and the bottom of the trenches at the first depth, the protection layer or stack of protection layers being different than the structured trench etch hard mask to ensure later selective removal of the protection layer or stack of protection layers with respect to the structured trench etch hard mask;
after the doped region is formed, etching the plurality of trenches deeper into the semiconductor substrate to a second depth greater than the first depth, adjacent ones of the trenches being separated from one another by a semiconductor mesa;
selectively removing the protection layer or stack of protection layers with respect to the structured trench etch hard mask; and
forming a body region above the doped region in the semiconductor mesas.
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Abstract
A method of manufacturing a semiconductor device includes: etching a plurality of trenches to a first depth in a semiconductor substrate; doping a region of the semiconductor substrate surrounding a bottom of the trenches at the first depth to form a doped region in the semiconductor substrate; after the doped region is formed, etching the plurality of trenches deeper into the semiconductor substrate to a second depth greater than the first depth, adjacent ones of the trenches being separated from one another by a semiconductor mesa; and forming a body region above the doped region in the semiconductor mesas.
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19 Claims
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1. A method of manufacturing a semiconductor device, the method comprising:
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etching a plurality of trenches to a first depth in a semiconductor substrate by forming a structured trench etch hard mask on a first main surface of the semiconductor substrate and etching the plurality of trenches to the first depth in the semiconductor substrate through openings in the structured trench etch hard mask; doping a region of the semiconductor substrate surrounding a bottom of the trenches at the first depth to form a doped region in the semiconductor substrate; before the doped region is formed, forming a protection layer or stack of protection layers on sidewalls and the bottom of the trenches at the first depth, the protection layer or stack of protection layers being different than the structured trench etch hard mask to ensure later selective removal of the protection layer or stack of protection layers with respect to the structured trench etch hard mask; after the doped region is formed, etching the plurality of trenches deeper into the semiconductor substrate to a second depth greater than the first depth, adjacent ones of the trenches being separated from one another by a semiconductor mesa; selectively removing the protection layer or stack of protection layers with respect to the structured trench etch hard mask; and forming a body region above the doped region in the semiconductor mesas. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 16, 17, 18, 19)
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14. A method of manufacturing a semiconductor device, the method comprising:
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etching a trench to a first depth in a semiconductor substrate using a structured trench etch hard mask; forming a protection layer or stack of protection layers on sidewalls and a bottom of the trench at the first depth, the protection layer or stack of protection layers being different than the structured trench etch hard mask to ensure later selective removal of the protection layer or stack of protection layers with respect to the structured trench etch hard mask; doping a region of the semiconductor substrate surrounding a bottom of the trench at the first depth to form an n-type hole potential barrier; after the n-type hole potential barrier is formed, etching the trench deeper into the semiconductor substrate to a second depth greater than the first depth; and selectively removing the protection layer or stack of protection layers with respect to the structured trench etch hard mask. - View Dependent Claims (15)
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Specification