Method for preventing the formation of recesses in borophosphosilicate glass

• US 6,165,694 A
• Filed: 02/13/1998
• Issued: 12/26/2000
• Est. Priority Date: 09/20/1997
• Status: Expired due to Term

• Current Assignee: United Microelectronics Corporation
• Original Assignee: United Semiconductor Corp. (United Microelectronics Corporation)
• Inventors: Liu, Tsan-Wen
• Primary Examiner(s): Duda, Kathleen
• Application Number:
  US09/023,235
• Time in Patent Office: 1,047 Days
• Field of Search: 430/313, 430/314, 430/327, 134/1.3, 134/42
• US Class Current: 430/313
• CPC Class Codes: H01L 21/76802 by forming openings in dielectrics
• CPC Class Codes: H01L 21/76829 characterised by the formation of thin functional dielectric layers, e.g. dielectric etch-stop, barrier, capping or liner layers

Abstract

A method for preventing the formation of recesses in the surface of a borophosphosilicate glass layer comprising the step of first forming a borophosphosilicate glass layer over a substrate, then forming a silicon nitride film having a thickness of about 300Å to 1000Å over the borophosphosilicate glass layer. Next, contact windows are formed, followed by cleaning with an RCA solution. The silicon nitride film provides a protective function preventing the formation of recesses on the borophosphosilicate glass surface. Consequently, no short-circuiting metal bridges caused by metal in the recesses after the deposition of metallic conducting wires are formed.

Claims

1. A method for preventing the formation of recesses in borophosphosilicate glass used for the planarization of a substrate, comprising the steps of:

forming a borophosphosilicate glass layer over a substrate;

forming an insulating layer on the borophosphosilicate glass (BPSG) layer to prevent formation of recesses on the surface of the BPSG layer during a cleaning process;

removing portions of the insulating layer and the borophosphosilicate glass layer to form a plurality of contact windows; and

after forming the contact windows, cleaning exposed surfaces of the remaining insulating layer on the remaining BPSG layer with a cleaning solution.

2. The method of claim 1, wherein the step of forming the insulating layer includes depositing a thin film of silicon nitride.

3. The method of claim 2, wherein the silicon nitride film has a thickness of 300Å

to 1000Å

.

4. The method of claim 2, wherein the step of forming the silicon nitride film includes using a low pressure chemical vapor deposition method.

5. The method of claim 1, wherein the step of removing portions of the insulating layer and the borophosphosilicate glass layer includes using photolithographic and etching processes.

6. The method of claim 4, wherein the step of removing portions of the insulating layer and the borophosphosilicate glass layer includes the following substeps:

forming a photoresist layer over the insulating layer;

patterning the photoresist layer to form a mask, then removing portions of the insulating layer and the borophosphosilicate glass layer to form a plurality of contact windows; and

removing the photoresist layer.

7. A method for preventing the formation of recesses in borophosphosilicate glass, comprising the steps of:

providing a substrate;

forming a borophosphosilicate glass layer over the substrate;

forming an insulating layer on the borophosphosilicate glass (BPSG) layer to prevent formation of recesses on the surface of the BPSG layer during a cleaning process;

forming a photoresist layer over the insulating layer;

patterning the photoresist layer to form a mask, and then removing portions of the insulating layer and the borophosphosilicate glass layer to form a plurality of contact windows;

removing the photoresist layer; and

cleaning the exposed surfaces of the remaining insulating layer on the remaining BPSG layer with a cleaning solution.

8. The method of claim 7, wherein the step of forming the insulating layer includes depositing a thin film of silicon nitride.

9. The method of claim 8, wherein the step of forming the silicon nitride film includes using a low pressure chemical vapor deposition method.

10. The method of claim 8, wherein the silicon nitride film has a thickness of 300Å

to 1000Å

.