Effect of abrasive material properties on polishing rate selectivity of nitrogen-doped Ge2Sb2Te5to SiO2film in chemical mechanical polishing

We investigated the polishing rate and selectivity of nitrogen-doped Ge2Sb2Te5(NGST) to SiO2film for different abrasive materials (colloidal silica, fumed silica, and ceria abrasives). They both were strongly dependant on abrasive material properties. The polishing rate of nitrogen-doped NGST decreased in the order ceria, fumed silica, and colloidal silica abrasives, which was determined by abrasive material properties, such as abrasive hardness, crystal structure, and primary and secondary abrasive sizes. In addition, the polishing rate slope of NGST film was not significantly different for different abrasive materials, indicating that the polishing of NGST film is mechanical dominant polishing. In contrast, the polishing rate slope of SiO2film decreased in the order ceria, fumed silica, and colloidal silica abrasives, indicating that the polishing of SiO2film is chemical dominant polishing. Furthermore, the difference in polishing rate slopes between NGST and SiO2film gave a polishing rate selectivity of NGST to SiO2film higher than 100:1 with colloidal silica abrasive.

Download Full-text

Measuring Surface Uniformity in Chemical Mechanical Polishing

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.76-78.459 ◽

2009 ◽

Vol 76-78 ◽

pp. 459-464

Author(s):

Jae Won Baik ◽

Chang Wook Kang

Keyword(s):

Chemical Mechanical Polishing ◽

Geometric Mean ◽

Mechanical Polishing ◽

Wafer Surface ◽

Semiconductor Wafer ◽

Statistical Process ◽

Significant Step ◽

The Difference ◽

Thickness Variations ◽

The Stability

Chemical mechanical polishing (CMP) is a technique used in semiconductor fabrication for planarizing the top surface of an in-process semiconductor wafer. Especially, Post-CMP thickness variations are known to have a severe impact on the stability of downstream processes and ultimately on device yield. Hence understanding how to quantify and characterize this non-uniformity is significant step towards statistical process control to achieve higher quality and enhanced productivity. The main reason is that the non-uniformed interface between the wafer and the machine-pad adversely affects the polishing performance and ultimate surface uniformity. The purpose of this paper is to suggest a new measure that estimates the uniformity of wafer surface considering the difference of the amount of abrasion between the center and the edge. This new measure which is called the Coefficient of Uniformity is defined as the following ratio: Geometric Mean (GM) / Arithmetic Mean (AM). This metric can be evaluated regionally to quantify the non-uniformity on the wafer surface from the center to the edge. Further simulations show that this new measure is insensitive to shift of the wafer center and sensitive to shift of the wafer edge. This trend indicates that this new measure is a very useful to test the non-uniformity of wafer after CMP polishing.

Download Full-text

Effect of Process Parameters on Material Removal Rate in Chemical Mechanical Polishing of 6H-SiC(0001)

Materials Science Forum ◽

10.4028/www.scientific.net/msf.600-603.831 ◽

2008 ◽

Vol 600-603 ◽

pp. 831-834 ◽

Cited By ~ 9

Author(s):

Joon Ho An ◽

Gi Sub Lee ◽

Won Jae Lee ◽

Byoung Chul Shin ◽

Jung Doo Seo ◽

...

Keyword(s):

Material Removal Rate ◽

Chemical Mechanical Polishing ◽

Material Removal ◽

Colloidal Silica ◽

Removal Rate ◽

Mechanical Polishing ◽

Diamond Particles ◽

Average Grain Size ◽

Silica Slurry ◽

Sic Wafer

2inch 6H-SiC (0001) wafers were sliced from the ingot grown by a conventional physical vapor transport (PVT) method using an abrasive multi-wire saw. While sliced SiC wafers lapped by a slurry with 1~9㎛ diamond particles had a mean height (Ra) value of 40nm, wafers after the final mechanical polishing using the slurry of 0.1㎛ diamond particles exhibited Ra of 4Å. In this study, we focused on investigation into the effect of the slurry type of chemical mechanical polishing (CMP) on the material removal rate of SiC materials and the change in surface roughness by adding abrasives and oxidizer to conventional KOH-based colloidal silica slurry. The nano-sized diamond slurry (average grain size of 25nm) added in KOH-based colloidal silica slurry resulted in a material removal rate (MRR) of 0.07mg/hr and the Ra of 1.811Å. The addition of oxidizer (NaOCl) in the nano-size diamond and KOH based colloidal silica slurry was proven to improve the CMP characteristics for SiC wafer, having a MRR of 0.3mg/hr and Ra of 1.087Å.

Download Full-text

Chemical Mechanical Polishing of Gallium Nitride with Colloidal Silica

Journal of The Electrochemical Society ◽

10.1149/2.024112jes ◽

2011 ◽

Vol 158 (12) ◽

pp. H1206 ◽

Cited By ~ 43

Author(s):

Hideo Aida ◽

Hidetoshi Takeda ◽

Koji Koyama ◽

Haruji Katakura ◽

Kazuhiko Sunakawa ◽

...

Keyword(s):

Gallium Nitride ◽

Chemical Mechanical Polishing ◽

Colloidal Silica ◽

Mechanical Polishing

Download Full-text

Study on the Influence of Sapphire Crystal Orientation on Its Chemical Mechanical Polishing

Applied Sciences ◽

10.3390/app10228065 ◽

2020 ◽

Vol 10 (22) ◽

pp. 8065

Author(s):

Linlin Cao ◽

Xiang Zhang ◽

Julong Yuan ◽

Luguang Guo ◽

Teng Hong ◽

...

Keyword(s):

Material Removal Rate ◽

Material Properties ◽

Chemical Mechanical Polishing ◽

Crystal Orientation ◽

Material Removal ◽

Removal Rate ◽

Substrate Material ◽

Mechanical Polishing ◽

Sapphire Crystal ◽

Research Objects

Sapphire has been the most widely used substrate material in LEDs, and the demand for non-C-planes crystal is increasing. In this paper, four crystal planes of the A-, C-, M- and R-plane were selected as the research objects. Nanoindentation technology and chemical mechanical polishing technology were used to study the effect of anisotropy on material properties and processing results. The consequence showed that the C-plane was the easiest crystal plane to process with the material removal rate of 5.93 nm/min, while the R-plane was the most difficult with the material removal rate of 2.47 nm/min. Moreover, the research results have great guiding significance for the processing of sapphire with different crystal orientations.

Download Full-text

Study on Chemical Mechanical Polishing Technology of Copper

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.373-374.820 ◽

2008 ◽

Vol 373-374 ◽

pp. 820-823

Author(s):

Sheng Li Wang ◽

Y.J. Yuan ◽

Yu Ling Liu ◽

X.H. Niu

Keyword(s):

Chemical Mechanical Polishing ◽

Colloidal Silica ◽

Removal Rate ◽

Mechanical Polishing ◽

Alkali Concentration ◽

Copper Films ◽

Optimum Conditions ◽

Slurry Flow Rate ◽

Polishing Pressure ◽

Oxidizer Concentration

Chemical mechanical polishing (CMP) of copper films in alkaline slurries was investigated. In the copper CMP, the slurry was made by adding colloidal silica abrasive to de-ionized water.The organic alkali was added to adjust the pH, H2O2 was used as an oxidizer.The effects of varying polishing temperature, polishing pressure, slurry flow rate, organic alkali concentration and oxidizer concentration on removal rate were investigated in order to determine the optimum conditions for those parameters. It is shown the chemical composition of the slurry was 2%~3% oxidizer concentration, 3% organic alkali concentration and proper amount surfactant is reasonable. The solid concentration of the polishing slurry was fixed at 20% by weight. The removal rate of copper could reach 700nm/min and the surface roughness after CMP was 0.49nm.

Download Full-text

Preparation of cobalt‐doped colloidal silica abrasives and their chemical mechanical polishing performances on sapphire

Micro & Nano Letters ◽

10.1049/mnl.2015.0292 ◽

2015 ◽

Vol 10 (11) ◽

pp. 657-661 ◽

Cited By ~ 7

Author(s):

Pan Ma ◽

Hong Lei ◽

Ruling Chen

Keyword(s):

Chemical Mechanical Polishing ◽

Colloidal Silica ◽

Mechanical Polishing

Download Full-text

Chemical-Mechanical Polishing of Wafers with Copper Film by Nano-Scale Abrasives

Materials Science Forum ◽

10.4028/www.scientific.net/msf.594.181 ◽

2008 ◽

Vol 594 ◽

pp. 181-186

Author(s):

Jhy Cherng Tsai ◽

Jin Fong Kao

Keyword(s):

Citric Acid ◽

Size Effect ◽

Surface Quality ◽

Chemical Mechanical Polishing ◽

Colloidal Silica ◽

Removal Rate ◽

Copper Film ◽

Mechanical Polishing ◽

Al2o3 Powder ◽

Abrasive Size

In this paper, experiments are designed and conducted to investigate the effects of abrasive size for Chemical-Mechanical Polishing (CMP) of copper film under different additives in HNO3-based polishing slurries. Alumina modified colloidal silica 100S (φ26nm), 200S (φ40nm) and Al2O3 (φ90nm), are used as polishing abrasives in this study. Experiments showed the following results. (1) With citric acid as an additive to slurry, the removal rate (RR) of the CMP process increases with abrasive size. Surface quality, however, becomes worse at the same time. (2) With benzotriazole (BTA) as an additive, RR of the slurry with Al2O3 powder is slightly higher but it does not increase with the abrasive size in general. Surface quality tends to be worse at the same time though it is not as strong as that in the slurry with citric acid as the additive. (3) The size effect of abrasive on RR with citric acid as additive is stronger than that with BTA.

Download Full-text

Preparation of Mg-doped colloidal silica abrasive and its chemical mechanical polishing performances on silicon wafer

2016 China Semiconductor Technology International Conference (CSTIC) ◽

10.1109/cstic.2016.7464032 ◽

2016 ◽

Author(s):

Pan Ma ◽

Hong Lei

Keyword(s):

Silicon Wafer ◽

Chemical Mechanical Polishing ◽

Colloidal Silica ◽

Mechanical Polishing ◽

Mg Doped

Download Full-text

Study on effect of the surface variation of colloidal silica abrasive during chemical mechanical polishing of sapphire

Japanese Journal of Applied Physics ◽

10.7567/jjap.56.07kb01 ◽

2017 ◽

Vol 56 (7S2) ◽

pp. 07KB01 ◽

Cited By ~ 8

Author(s):

Natthaphon Bun-Athuek ◽

Yutaka Yoshimoto ◽

Koya Sakai ◽

Panart Khajornrungruang ◽

Keisuke Suzuki

Keyword(s):

Chemical Mechanical Polishing ◽

Colloidal Silica ◽

Mechanical Polishing ◽

Surface Variation

Download Full-text

Effect of Polishing Pad Material Properties on Chemical Mechanical Polishing (Cmp) Processes

MRS Proceedings ◽

10.1557/proc-337-637 ◽

1994 ◽

Vol 337 ◽

Cited By ~ 36

Author(s):

Rajeev Bajaj ◽

Mukesh Desai ◽

Rahul Jairath ◽

Matthew Stell ◽

Robert Tolles

Keyword(s):

Material Properties ◽

Chemical Mechanical Polishing ◽

Material Removal ◽

Cellular Structure ◽

Mechanical Response ◽

Removal Rate ◽

Mechanical Polishing ◽

Cold Flow ◽

Polymer Properties ◽

Polishing Pads

ABSTRACTChemical mechanical polishing (CMP) technology has successfully met the stringent requirements of ultraplanarized surfaces in semiconductor manufacture. Commonly, polyurethane based pads have been used to achieve this level of planarization. Recent studies have shown that the material properties of polishing pads used in the CMP process strongly influence the ability to reduce topography. In addition, past work has shown that in the absence of pad regeneration, polishing rate drops dramatically with polishing time. This decrease in material removal rate is believed to coincide with deterioration of the pad surface due to “cold flow” and/or “caking” of the pad material. This study attempts to correlate the intrinsic polymer properties and cellular structure of the pad material to CMP process indices like polishing rate and planarity. For example, the drop off in removal rate as a function of time can be attributed to the mechanical response of polyurethanes under conditions of critical shear. Moreover, planarity achieved is a function of pad stiffness - which itself is dependant upon intrinsic polymer stiffness and cell density.

Download Full-text