Methods of adhesion promoter between low-K layer and underlying insulating layer

• US 6,472,335 B1
• Filed: 10/19/1998
• Issued: 10/29/2002
• Est. Priority Date: 10/19/1998
• Status: Expired due to Term

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Tsai, Chia-Shiung, Tao, Hun-Jan, Cheng, Yao-Yi
• Primary Examiner(s): Whitehead, Jr., Carl
• Assistant Examiner(s): VOCKRODT, JEFF B
• Application Number:
  US09/175,019
• Time in Patent Office: 1,471 Days
• Field of Search: 438/624, 438/665, 438/756, 438/757, 438/786, 438/906, 438/958, 438/964, 438/763, 438/780
• US Class Current: 438/780
• CPC Class Codes: H01L 21/02118 carbon based polymeric organic or inorganic material, e.g. polyimides, poly cyclobutene or PVC polymers per se C08G, photoresist per se G03F
• CPC Class Codes: H01L 21/0214 the material being a silicon oxynitride, e.g. SiON or SiON:H
• CPC Class Codes: H01L 21/022 the layer being a laminate, i.e. composed of sublayers, e.g. stacks of alternating high-k metal oxides adhesion layers or buffer layers H01L21/02304, H01L21/02362
• CPC Class Codes: H01L 21/02343 treatment by exposure to a liquid
• CPC Class Codes: H01L 21/31111 by chemical means
• CPC Class Codes: H01L 21/312 Organic layers, e.g. photoresist H01L21/3105, H01L21/32 take precedence; photoresists per se G03C
• CPC Class Codes: H01L 21/3122 layers comprising polysiloxane compounds
• CPC Class Codes: H01L 21/3124 layers comprising hydrogen silsesquioxane
• CPC Class Codes: H01L 21/3144 on silicon
• CPC Class Codes: H01L 21/31629 Deposition of halogen doped silicon oxide, e.g. fluorine doped silicon oxide
• CPC Class Codes: H01L 21/3185 of siliconnitrides
• CPC Class Codes: H01L 21/76801 characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing
• CPC Class Codes: Y10S 438/906 Cleaning of wafer as interim step
• CPC Class Codes: Y10S 438/958 Passivation layer
• CPC Class Codes: Y10S 438/964 Roughened surface

Abstract

The present invention provides a method improving the adhesion between inter metal dielectric (IMD) layers by performing a HF dip etch to treat the surface of an oxide, silicon nitride or Silicon oxynitride insulating layer before an overlying low-K layer is formed. The present invention provides a method of fabricating a low-K IMD layer 20 over an oxide, Silicon oxynitride (SiON), or nitride IMD layer 14 with improved adhesion. First, a 1st inter metal dielectric (IMD) layer 14 is formed over a substrate. Next, the invention'"'"'s novel HF dip etch is performed on the 1st IMD layer 14 to form a treated surface 16. Next, a 2nd BMD layer composed of a low-K material is formed over the rough surface 16 of the 1st IMD layer 14. The treated surface 16 improves the adhesion between a 1st IMD layer oxide (oxide, SiN or SiON) and a low k layer. Subsequent photoresist strip steps do not cause the 1st IMI layer 14 and the 2nd IMD layer 20 (low-K dielectric) to peel.

Claims

1. A method of fabricating a low-K second insulating layer over first insulating layer with improved adhesion, comprising the steps of:

a) forming a first insulating layer over a semiconductor structure;

said first insulating layer composed of Silicon oxynitride;

said first insulating layer having a surface;

b) treating said first insulating layer with HF under conditions sufficient to alter the condition of said surface thereby increasing the adhesion between said first insulating layer and a subsequently formed second insulating layer composed of a low-K dielectric material;

treating said first insulating layer includes dip etching said first insulating layer in 50;

1 HF in H₂O for a time in a range of between about 30 and 90 seconds to form a treated surface of said first insulating layer;

c) forming said second insulating layer on said surface of said first insulating layer;

said second insulating layer is comprised of poly(arlene ether);

d) forming a photoresist layer over said second insulating layer;

e) etching openings in said second insulating layer and said first insulating layer by using said photoresist layer as an etch mask;

said openings are dual damascene openings; and

f) wet stripping said photoresist layer using a photoresist stripper whereby said second insulating layer adheres to said first insulating layer without peeling;

said photoresist stripper is comprised of;

hydroxyl amine, 2-(2-aminoethoyy) ethanol, cathechol and an alkaline buffer.