Semiconductor structure formation

1. A method, comprising:

forming a silicate material to have a gradient borophosphosilicate glass (BPSG) stack on a semiconductor structure substrate, wherein forming the silicate material to have the gradient BPSG stack comprises:

varying concentrations of boron and phosphorous gradually in a linearly gradient manner from a stronger dopant concentration at a bottom portion of the silicate material to a lesser dopant concentration at a top portion of the silicate material;

forming a dopant concentration of boron of approximately 4.0 wt % at the bottom portion of the silicate material; and

forming a dopant concentration of boron of approximately 1.0 wt % at the top portion of the silicate material; and

etching a portion of the silicate material to form an opening within the silicate material having sidewalls, wherein the gradient BSPG stack comprises the varying concentrations of boron and phosphorous to reduce tapering of the sidewalls in response to the etching.

2. The method of claim 1 , wherein forming the silicate material to have the gradient BPSG stack comprises:

varying a dopant concentration of phosphorous in a linearly gradient manner from approximately 5.2 wt % at the bottom portion of the silicate material to approximately 4.2 wt % at the top portion of the silicate material.

3. A method, comprising:

forming a silicate material to have a gradient borophosphosilicate glass (BPSG) stack, the BPSG stack having a first portion and a second portion, wherein forming the silicate material to have the BPSG stack comprises:

forming the gradient BSPG stack to have varying concentrations of boron and phosphorous within the first portion, wherein a dopant concentration of boron is varied in a linearly gradient manner from approximately 4.0 wt % at a bottom portion of the silicate material and approximately 1.0 wt % at a transition point of the silicate material;

forming the gradient BSPG stack to have non-varying concentrations of boron and phosphorous within the second portion; and

etching a portion of the silicate material to form an opening within the silicate material having sidewalls, wherein the concentrations of boron and phosphorous within the first portion and the second portion reduce tapering of the sidewalls in response to the etching.

4. The method of claim 3 , wherein the concentrations of boron and phosphorous in the first portion is greater than the concentrations of boron and phosphorous in the second portion.

5. The method of claim 3 , wherein the silicate material extends from the bottom portion to a top portion and the first portion extends a first distance between the bottom portion of the silicate material and the transition point positioned below the top portion of the silicate material.

6. The method of claim 5 , wherein the second portion extends a second distance between the top portion of the silicate material and the transition point of the silicate material.

7. The method of claim 6 , wherein the first distance is approximately 4800 angstroms and the second distance is approximately 1300 angstroms.

8. The method of claim 3 , wherein forming the silicate material to have the BPSG stack comprises varying a dopant concentration of phosphorous in a linearly gradient manner from approximately 5.2 wt % at the bottom portion of the silicate material and approximately 4.2 wt % at the transition point of the silicate material.

9. The method of claim 3 , wherein forming the silicate material to have the gradient BPSG stack comprises:

forming a dopant concentration of boron of approximately 1.0 wt % in a non-varying linear manner between the top portion of the silicate material and the transition point of the silicate material; and

forming a dopant concentration of phosphorous of approximately 5.2 wt % in a non-varying linear manner between the top portion of the silicate material and the transition point of the silicate material.

10. The method of claim 3 , wherein etching the portion of the silicate material to form the opening within the silicate material comprises utilizing one of a vapor etch process, a wet etch process, and a dry etch process.

11. A method, comprising:

forming a first silicate material having a gradient borophosphosilicate glass (BPSG) stack on a substrate;

forming the gradient BSPG stack to have varying concentrations of boron and phosphorous, wherein forming the gradient BSPG stack to have varying concentrations of boron and phosphorous comprises:

varying a dopant concentration of boron in a linearly gradient manner within a first portion from approximately 4.0 wt % at a bottom portion of the first silicate material to approximately 1.0 wt % at a transition point of the first silicate material; and

varying a dopant concentration of phosphorous in a linearly gradient manner within the first portion from approximately 5.2 wt % at the bottom portion of the silicate material to approximately 4.2 wt % at the transition point of the first silicate material;

forming a first nitride material on the first silicate material;

forming a second silicate material on the first nitride material;

forming a second nitride material on the second silicate material; and

performing etching through the first silicate material, the first nitride material, the second silicate material, and the second nitride material to form an opening having sidewalls, wherein the concentrations of boron and phosphorous reduce tapering of the sidewalls along the first silicate material in response to the etching.

12. The method of claim 11 , wherein forming the gradient BSPG stack to have varying concentrations of boron and phosphorous comprises;

and

forming the gradient BSPG stack to have non-varying concentrations of boron and phosphorous within a second portion of the first silicate material.

13. The method of claim 11 , wherein the first silicate material further comprises a second portion, and wherein the first silicate material extends from the bottom portion to a top portion, the first portion extends a first distance between the bottom portion of the first silicate material and the transition point positioned below the top portion of the first silicate material.

14. The method of claim 13 , wherein the second portion extends a second distance between the top portion of the silicate material and the transition point.

15. The method of claim 13 , wherein the first distance is greater than the second distance.

16. A method, comprising:

forming a silicate material to have a gradient borophosphosilicate glass (BPSG) stack on a semiconductor structure substrate, wherein forming the silicate material to have the gradient BPSG stack comprises:

varying concentrations of boron and phosphorous gradually from a stronger dopant concentration at a bottom portion of the silicate material to a lesser dopant concentration at a top portion of the silicate material;

forming a dopant concentration of phosphorous of approximately 5.2 wt % at the bottom portion of the silicate material; and

forming a dopant concentration of phosphorous of approximately 4.2 wt % at the top portion of the silicate material; and

etching a portion of the silicate material to form an opening within the silicate material having sidewalls, wherein the gradient BSPG stack comprises the varying concentrations of boron and phosphorous to reduce tapering of the sidewalls in response to the etching.