Self-registered, thermal processing technique using a pulsed heat source

Claim 1

A method of thermal processing selected areas of an exposed surface of a workpiece, comprising the steps of: (a) providing a workpiece having an exposed surface comprising active areas of a first region to be heated for thermal processing thereof and passive areas of a second region to be maintained at a lower temperature than said active areas for minimizing thermal processing thereof; (b) providing a pulse-mode source of blanket heat energy with predetermined energy, pulse duration, and pulse interval operating parameters; (c) selecting the energy parameter of said heat energy source to achieve heat absorption in said first region of said workpiece, so as to raise the temperature of said active areas, while minimizing heat absorption in said second region, so as to limit any temperature rise of said passive areas; (d) selecting the pulse duration of said heat energy source to be sufficiently short and the pulse interval of said heat energy source to be sufficiently long so as to minimize stray heat transfer to said passive areas from either said active areas or any incidentally-heated regions of said workpiece, and thereby to minimize any temperature rise of said passive areas; (e) directing heat energy from said source of blanket heat energy in blanket fashion to said first and second regions of said workpiece; and (f) contacting said exposed surface of said workpiece with a heat-activated reactant, whereby thermal processing with said reactant occurs selectively at said active areas of said exposed surface.

Claim 2

A method of thermal processing selected areas of an exposed surface of a workpiece, comprising the steps of: (a) providing a workpiece having an exposed surface comprising active areas of a first region to be heated for thermal processing thereof and passive areas of a second region to be maintained at a lower temperature than said active areas for minimizing thermal processing thereof; (b) providing a pulse-mode source of blanket heat energy with predetermined energy, pulse duration, and pulse interval operating parameters; (c) selecting the energy parameter of said heat energy source to achieve heat absorption in said first region of said workpiece, so as to raise the temperature of said active areas, while minimizing heat absorption in said second region, so as to limit any temperature rise of said passive areas; (d) selecting the pulse duration of said heat energy source to be sufficiently short and the pulse interval of said heat energy source to be sufficiently long so as to minimize stray heat transfer to said passive areas from either said active areas or any incidentally-heated regions of said workpiece, and thereby to minimize any temperature rise of said passive areas; (e) directing heat energy from said source of blanket heat energy in blanket fashion to said first and second regions of said workpiece; and (f) contacting said exposed surface of said workpiece with a heat-activated reactant, whereby thermal processing with said reactant occurs selectively at said active areas of said exposed surface.

Claim 22

A method of thermal processing selected areas of an exposed surface of a silicon semiconductor device, comprising the steps of: (a) providing a generally plate-shaped semiconductor device having an exposed surface comprising active areas of silicon semiconductor material to be heated for thermal processing thereof and passive areas of dielectric material to be maintained at a lesser temperature than said active areas for minimizing thermal processing thereof; (b) providing a pulse-mode laser source of blanket heat energy with predetermined energy wavelength, pulse duration, and pulse interval operating parameters; (c) selecting the wavelength of said heat energy means to be less than 1.1 microns to achieve heat absorption in said silicon semiconductor material, so as to raise the temperature thereof, while minimizing heat absorption in said dielectric material, so as to limit any temperature rise thereof; (d) selecting the pulse duration of said heat energy source to be sufficiently short and the pulse interval of said heat energy source to be sufficiently long so as to minimize stray heat transfer to said passive areas from either said active areas or any incidentally-heated regions of said semiconductor device, and thereby to limit any temperature rise of said passive areas; (e) directing heat energy from said source of blanket heat energy in blanket fashion to said silicon and dielectric material of said semiconductor device; and (f) contacting said exposed surface of said workpiece with a heat-activated reactant, whereby thermal processing with said reactant occurs selectively at said active areas of said exposed surface.

Claim 23

A method of thermal processing selected areas of an exposed surface of a silicon semiconductor device, comprising the steps of: (a) providing a generally plate-shaped semiconductor device having an exposed surface comprising active areas of silicon semiconductor material to be heated for thermal processing thereof and passive areas of dielectric material to be maintained at a lesser temperature than said active areas for minimizing thermal processing thereof; (b) providing a pulse-mode laser source of blanket heat energy with predetermined energy wavelength, pulse duration, and pulse interval operating parameters; (c) selecting the wavelength of said heat energy means to be less than 1.1 microns to achieve heat absorption in said silicon semiconductor material, so as to raise the temperature thereof, while minimizing heat absorption in said dielectric material, so as to limit any temperature rise thereof; (d) selecting the pulse duration of said heat energy source to be sufficiently short and the pulse interval of said heat energy source to be sufficiently long so as to minimize stray heat transfer to said passive areas from either said active areas or any incidentally-heated regions of said semiconductor device, and thereby to limit any temperature rise of said passive areas; (e) directing heat energy from said source of blanket heat energy in blanket fashion to said silicon and dielectric material of said semiconductor device; and (f) contacting said exposed surface of said workpiece with a heat-activated reactant, whereby thermal processing with said reactant occurs selectively at said active areas of said exposed surface.