Method for tungsten deposition without fluorine-contaminated silicon substrate
AssigneeProMOS Technologies Inc.
InventorChun-Yao Yen
Life of this patent
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Abstract
A method for forming tungsten structures over silicon substrates, including the following steps. A silicon substrate is having a patterned dielectric layer formed thereon defining a tungsten structure opening is provided. The silicon substrate is pre-heated to a temperature of from about 430 to 440° C. A Si-rich WSx layer is formed over the patterned dielectric layer, lining the tungsten structure opening. A WSix nucleation layer is formed over the Si-rich WSix layer. A tungsten bulk layer is formed over the WSix nucleation layer, filling the tungsten structure opening, whereby fluorine attack of the Si substrate is minimized.
Claims23
A method for forming tungsten structures over silicon substrates, including the steps of:
- providing a silicon substrate having a patterned dielectric layer formed thereon defining a tungsten structure opening;
- pre-heating the silicon substrate to a first temperature;
- forming a Si-rich WSix layer over the patterned dielectric layer at a second temperature, lining the tungsten structure opening;
- wherein the first temperature is from about 5 to 15° C. higher than the second temperature;
- forming a WSix nucleation layer over the Si-rich WSix layer;
- and
- forming a tungsten bulk layer over the WSix nucleation layer, filling the tungsten structure opening;
- whereby fluorine attack of the Si substrate is minimized.
A method for forming tungsten structures over silicon substrates, including the steps of:
- providing a silicon substrate having a patterned dielectric layer formed thereon defining a tungsten structure opening;
- pre-heating the silicon substrate to a preheating temperature of from about 430 to 440° C.;
- forming a Si-rich WSix layer over the patterned dielectric layer, lining the tungsten structure opening;
- wherein the formation of the Si-rich WSix layer is achieved at a temperature that is from about 5 to 15° C. lower than the pre-heating temperature;
- forming a WSix nucleation layer over the Si-rich WSix layer;
- forming a tungsten bulk layer over the WSix nucleation layer, filling the tungsten structure opening;
- and
- planarizing the structure to remove the excess of the tungsten layer, WSix the nucleation layer, and the Si-rich WSix film/layer from the patterned dielectric layer to form a planarized composite tungsten plug;
- whereby fluorine attack of the Si substrate is minimized.
A method for forming tungsten structures over silicon substrates, including the steps of:
- providing a silicon substrate having a patterned dielectric layer formed thereon defining a tungsten structure opening;
- forming a barrier layer over the patterned dielectric layer, lining the tungsten structure opening;
- pre-heating the silicon substrate to a pre-heating temperature of from about 430 to 440° C.;
- forming a Si-rich WSix layer over the barrier layer;
- wherein the formation of the Si-rich WSix layer is achieved at a temperature that is from about 5 to 15° C. lower than the pre-heating temperature;
- forming a WSix nucleation layer over the Si-rich WSix layer;
- forming a tungsten bulk layer over the WSix nucleation layer, filling the tungsten structure opening;
- and
- planarizing the structure to remove the excess of the tungsten layer, WSix the nucleation layer, and the Si-rich WSix film/layer from the patterned dielectric layer to form a planarized composite tungsten plug;
- whereby fluorine attack of the Si substrate is minimized.
Dependencies are inferred from the claim text.