Transistor sidewall spacer stress modulation
First Claim
1. An integrated circuit, comprising;
- first and second transistors, each including a gate electrode over a gate dielectric over a semiconductor substrate;
first spacer structures adjacent sidewalls of the first gate electrode and second spacer structures adjacent sidewalls of the second gate electrode; and
first source/drain regions within the substrate and self-aligned to the first spacer structures and second source/drain regions within the substrate and self-aligned to the second spacer structures, wherein the first and second sidewall spacer structures comprise silicon nitride having a Si/N ratio of less than 0.8 and further wherein the first sidewall spacer structures include a distribution of an impurity selected from Xenon and Germanium.
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Accused Products
Abstract
A semiconductor fabrication process and the resulting integrated circuit include forming a gate electrode (116) over a gate dielectric (104) over a semiconductor substrate (102). A spacer film (124) exhibiting a tensile stress characteristic is deposited over the gate electrode (116). The stress characteristics of at least a portion of the spacer film is then modulated (132, 192) and the spacer film (124) is etched to form sidewall spacers (160, 162) on the gate electrode sidewalls. The spacer film (124) is an LPCVD silicon nitride in one embodiment. Modulating (132) the spacer film (124) includes implanting Xenon or Germanium into the spacers (160) at an implant energy sufficient to break at least some of the silicon nitride bonds. The modulation implant (132) may be performed selectively or non-selectively either before or after etching the spacer film (124).
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Citations
18 Claims
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1. An integrated circuit, comprising;
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first and second transistors, each including a gate electrode over a gate dielectric over a semiconductor substrate; first spacer structures adjacent sidewalls of the first gate electrode and second spacer structures adjacent sidewalls of the second gate electrode; and first source/drain regions within the substrate and self-aligned to the first spacer structures and second source/drain regions within the substrate and self-aligned to the second spacer structures, wherein the first and second sidewall spacer structures comprise silicon nitride having a Si/N ratio of less than 0.8 and further wherein the first sidewall spacer structures include a distribution of an impurity selected from Xenon and Germanium. - View Dependent Claims (2, 3, 4)
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5. An integrated circuit, comprising:
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a plurality of gate electrodes overlying a gate dielectric overlying a semiconductor substrate; and sidewall spacers laterally disposed on either side of the gate electrodes, wherein at least a portion of the sidewall spacers include sidewall spacers exhibiting a first tensile stress and wherein at least a second portion of the sidewall spacers include sidewall spacers exhibiting a second tensile stress; wherein the sidewall spacers comprise silicon nitride; and wherein the second portion of the sidewall spacers further includes an implanted species. - View Dependent Claims (6, 7, 8, 9, 10, 11)
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12. A integrated circuit, comprising:
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silicon nitride spacers on sidewalls of a gate electrode overlying a semiconductor substrate; wherein at least some of the sidewall spacers include an implanted species; and wherein the stress characteristics of the sidewall spacers having the implanted species differ from the stress characteristics of other sidewall spacers. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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Specification