Forming nanotips
AssigneeInternational Business Machines Corporation
InventorsKangguo Cheng, Ramachandra Divakaruni, Juntao Li, Shogo Mochizuki
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Abstract
A nanotip apparatus which includes nanotips arranged in a pattern on a semiconductor base. Each of the nanotips have a pointed tip portion and a base portion in contact with the semiconductor base. Further, each of the nanotips include a gradient of silicon germanium (SiGe) with the highest concentration of germanium being at the pointed tip portion and the lowest concentration of germanium being at the base in contact with the semiconductor base. Also disclosed is a method in which the nanotips may be formed.
Claims20
A nanotip apparatus comprising a plurality of nanotips arranged in a pattern on a semiconductor base, each of the nanotips having a pointed tip and having a base portion in contact with the semiconductor base, each of the nanotips further comprising a gradient of silicon germanium (SiGe) extending continuously from the pointed tip to the semiconductor base with the highest concentration of germanium being at the pointed tip and the lowest concentration of germanium being at the base portion in contact with the semiconductor base.
A method comprising:
- forming a substrate comprising a silicon germanium (SiGe) gradient layer on a semiconductor base such that there is a greater concentration of germanium at a top of the SiGe layer away from the semiconductor base than at a bottom of the SiGe layer in contact with the semiconductor base;
- patterning the SiGe gradient layer to form SiGe pillars;
- depositing an oxide layer over and between the SiGe pillars;
- and
- oxidizing the SiGe pillars such that a top of the SiGe pillars is oxidized faster than a bottom of the SiGe pillars in contact with the silicon base, the oxidizing causing the silicon in the SiGe pillars to react with oxygen to form an oxide and be partially removed from the SiGe pillars such that tapered SiGe pillars are formed with the top of the SiGe pillars forming a tip and having a greater concentration of germanium at the tip than at the bottom of the pillars.
A method comprising:
- forming a substrate comprising an array of SiGe pillars on a semiconductor substrate, the SiGe pillars having a germanium gradient within the SiGe pillars such that there is a greater concentration of germanium at a top of the SiGe pillars away from the semiconductor base than at a bottom of the SiGe pillars in contact with the semiconductor base;
- and
- oxidizing the SiGe pillars such that tapered SiGe pillars are formed with the top of the SiGe pillars forming a tip and having a greater concentration of germanium at the tip than at the bottom of the pillars.
Dependencies are inferred from the claim text.