Atom implantation for reduction of compressive stress
Systems, apparatuses, and methods related to atom implantation for reduction of compressive stress are described. An example method may include patterning a working surface of a semiconductor, the working surface having a hard mask material formed over a dielectric material and forming a material having a lower refractive index (RI), relative to a RI of the hard mask material, over the hard mask material. The method may further include implanting atoms through the lower RI material and into the hard mask material to reduce the compressive stress in the hard mask material.
1. A method, comprising:
patterning a working surface of a semiconductor, the working surface having a hard mask material, which includes carbon (C), formed over a dielectric material;
forming a material having a lower refractive index (RI), relative to a RI of the hard mask material, over the hard mask material, wherein forming the material having the lower RI including formation of the lower RI material at a temperature of at least 200 degrees Celsius (° C.) to increase the compressive stress in the hard mask material; and
subsequent to forming the material having the lower RI over the hard mask material, implanting C atoms through the lower RI material and into the hard mask material to reduce a compressive stress in the hard mask material.
2. The method of claim 1 , further comprising forming the dielectric material from a silicon nitride material.
3. The method of claim 1 , further comprising forming the hard mask material from substantially pure carbon.
4. The method of claim 1 , further comprising forming the lower RI material from nitrous oxide (N 2 O) plasma at a temperature in a range of from 350 degrees Celsius (° C.) to 450° C.
5. The method of claim 1 , further comprising forming the lower RI material from nitrous oxide (N 2 O) and silane (SiH 4 ) at a temperature in a range of from 350 degrees Celsius (° C.) to 450° C.
6. The method of claim 1 , further comprising:
increasing the compressive stress in the hard mask material to at least 150 megapascals (MPa) by formation of the lower RI material over the hard mask material; and
subsequently reducing the increased compressive stress in the hard mask material to below 25 MPa by the C atoms being implanted into the hard mask material.
7. The method of claim 1 , further comprising:
forming a pillar of a semiconductor device from the lower RI material, the hard mask material, and the dielectric material; and
wherein implanting the atoms through the lower RI material and into the hard mask material reduces the compressive stress in the hard mask material and reduces a probability of an unintended bend of the pillar;
wherein the reduced probability is relative to the C atoms being implanted into the hard mask material prior to formation of the lower RI material over the hard mask material.
8. The method of claim 1 , further comprising:
implanting the C atoms into the hard mask material at:
a dose in a range of from 1×10 15 per square centimeter (/cm 2 ) to 1×10 16 /cm 2 ; and
an implant energy in a range of from 5 kiloelectron volts (keV) to 60 keV.