High aspect ratio MEMS devices and methods for forming the same
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorTe-Hao Lee
Life of this patent
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Abstract
An HF vapor etch etches high aspect ratio openings to form MEMS devices and other tightly-packed semiconductor devices with 0.2 um air gaps between structures. The HF vapor etch etches oxide plugs and gaps with void portions and oxide liner portions and further etches oxide layers that are buried beneath silicon and other structures and is ideally suited to release cantilevers and other MEMS devices. The HF vapor etches at room temperature and atmospheric pressure in one embodiment. A process sequence is provided that forms MEMS devices including cantilevers and lateral, in-plane electrodes that are stationary and vibration resistant.
Claims20
A method for forming a semiconductor device, said method comprising:
- providing a substrate with structures thereover, said structures spaced apart by gaps including gaps filled with oxide and gaps including voids and lined with oxides and at least some of said structures having a release oxide liner formed thereunder;
- and
- etching in an HF vapor that removes said oxides in said gaps and said release oxide liner.
A method for forming a semiconductor device, said method comprising:
- providing a substrate with structures thereover, said structures spaced apart by gaps including gaps filled with oxide and gaps including voids and lined with oxides and at least some of said structures having a release oxide liner formed thereunder;
- and
- etching in an HF vapor that removes said oxides in said gaps and said release oxide liner,
- wherein said structures are Si-based structures that include sections of silicon germanium.
A method for forming MEMS (micro electro mechanical system) devices, said method comprising:
- providing a substrate with discrete silicon-based portions disposed thereover, said discrete silicon-based portions spaced apart by oxide plugs and openings lined with oxide liners;
- fusion bonding a silicon wafer to said substrate;
- performing an HF vapor etching operation that etches said oxide plugs and said oxide liners in an HF vapor thereby producing gaps between said discrete silicon-based portions, said gaps defined by opposed sides of said discrete silicon-based portions;
- and
- further processing to form MEMS devices from at least some of said discrete silicon-based portions.
Dependencies are inferred from the claim text.