An analytical dishing and step height reduction model for chemical mechanical planarization (CMP)

2003 ◽  
Vol 16 (3) ◽  
pp. 477-485 ◽  
Author(s):  
Guanghui Fu ◽  
A. Chandra
Keyword(s):  
Chemical Mechanical Planarization ◽  
Step Height ◽  
Reduction Model ◽  
Height Reduction

An Analytical Dishing and Step Height Reduction Model for Chemical Mechanical Planarization (CMP)

2002 ◽  
Author(s):  
Guanghui Fu ◽  
Abhijit Chandra
Keyword(s):  
Chemical Mechanical Planarization ◽  
Design Tool ◽  
Step Height ◽  
Wafer Surface ◽  
Surface Geometry ◽  
Height Reduction ◽  
Proposed Model ◽  
Model Predictions ◽  
Feature Scale ◽  
Good Agreement

An analytical model for dishing and step height reduction in chemical mechanical planarization (CMP) of copper is presented. The model is based on the assumption that at the feature scale, high areas on the wafer experience higher pressure than low areas. The slurry is assumed to be Prestonian. The model delineates how dishing and step height reduction depend on slurry properties (selectivity and Preston’s constants), pad characteristics (stiffness and bending ability), polishing conditions (pressure, relative velocity and overpolishing) and wafer surface geometry (linewidth, pitch and pattern density). Model predictions are in good agreement with existing experimental observations. The present model facilitates understanding of the CMP process at the feature scale. Based on the proposed model, design avenues for decreasing dishing and increasing the speed of step height reduction may be explored through modification of appropriate parameters for slurry, pad and polishing conditions. The proposed model may also be used as a design tool for pattern layout to optimize the performance of the CMP process.

On the Pattern Dependency and Substrate Effects During Chemical-Mechanical Planarization for Ulsi Manufacturing

1999 ◽  
Vol 566 ◽  
Author(s):  
Wei-Tsu Tseng ◽  
James Jong-Lin Niu ◽  
Chi-Fa Lin
Keyword(s):  
Chemical Mechanical Planarization ◽  
Reduction Rate ◽  
Surface Profile ◽  
Step Height ◽  
Substrate Effects ◽  
Height Reduction ◽  
Pattern Density

The change of surface profile during chemical-mechanical planarization (CMP) is monitored continuously in this study. The influences from pattemn dependency and substrate effects are discussed. Step height reduction rate is a function of pattern density and down force. The rate decreases with time until planarization is achieved. As the polish approaches the patterns underneath, the interaction between substrate effects and pattern dependency results in the resurgence of step height. The implication of this newly found phenomenon is discussed.

Analytical Dishing and Step Height Reduction Model for CMP With a Viscoelastic Pad

2004 ◽  
Vol 151 (9) ◽  
pp. G583 ◽  
Author(s):  
Yongjin Guo ◽  
Abhijit Chandra ◽  
Ashraf-F. Bastawros
Keyword(s):  
Step Height ◽  
Reduction Model ◽  
Height Reduction

Step height removal mechanism of chemical mechanical planarization (CMP) for sub-nano-surface finish

Wear ◽  
2010 ◽  
Vol 268 (3-4) ◽  
pp. 505-510 ◽  
Author(s):  
Ji Chul Yang ◽  
Dong Won Oh ◽  
Gae Won Lee ◽  
Chang Lyung Song ◽  
Taesung Kim
Keyword(s):  
Surface Finish ◽  
Chemical Mechanical Planarization ◽  
Step Height ◽  
Removal Mechanism

Effects of Alkaline Nano-SiO2 Abrasive on Planarization of 300mm Copper Patterned Wafer

2013 ◽  
Vol 634-638 ◽  
pp. 2949-2954
Author(s):  
Xin Liang Tang ◽  
Yu Ling Liu ◽  
Hong Yuan Zhang ◽  
Jie Bao
Keyword(s):  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Initial Step ◽  
Step Height ◽  
Copper Removal ◽  
Copper Wafers

Silica abrasive plays an important role in chemical mechanical planarization (CMP) of copper. In this paper, effect of different silica abrasive concentrations on copper removal rate and planarization performance of copper was investigated. The results show that the copper removal rate was increased as the concentration of silica abrasive increase. However, excessive abrasive will lead to a decreased copper removal rate. The initial step height values of the multilayer copper wafers were all about 2500Å, and after being polished for 30s, the remaining values of step height of slurry A, B, C and D were 717 Å, 906 Å, 1222 Å and 1493 Å. It indicates that alkaline copper slurries with different abrasive concentrations all had a good planarization performance on copper patterned wafer CMP. As the abrasive concentration increased, the planarization capability was enhanced.

Yield Improvement via minimization of step height non-uniformity in Chemical Mechanical Planarization (CMP)

2005 ◽  
Vol 867 ◽  
Author(s):  
Muthukkumar Kadavasal ◽  
Sutee Eamkajornsiri ◽  
Abhijit Chandra ◽  
Ashraf F. Bastawros
Keyword(s):  
Chemical Mechanical Planarization ◽  
Open Loop ◽  
Step Height ◽  
Control Algorithms ◽  
Open Loop Control ◽  
Time Step ◽  
Surface Evolution ◽  
Loop Control ◽  
Final Surface ◽  
Pattern Density

AbstractObtaining local and global planarity is one of the prime criteria in dielectric and metal planarizations. Although Chemical Mechanical Planarization (CMP) helps us achieve this criterion in constant pattern density surfaces, the same is not true for variable pattern density surfaces this results in formation of global step heights across the die. This paper provides a pressure open loop control algorithms for obtaining planarity across a die containing variations in pattern densities. Based on the variation of pattern density and surface heights across the die, the surfaces are separated into zones and the pressure is varied spatially and/or temporally to obtain uniform surface heights, with enhanced step height uniformity. One of the algorithms looks ahead and recalculates/modifies the pressure values by identifying the step heights that could be formed after a specified time step. The final surface predictions have improved uniformity on the upper surface as well as on the step heights across the entire die. The simulation would help us track the polishing process for each time step and guide us with the optimized pressure values that can be applied in order to an uniform final surface evolution.

Effect of TT-LYK as the Inhibitor on Step Height Reduction for Copper CMP

2019 ◽  
Author(s):  
Jiakai Zhou ◽  
Xinhuan Niu ◽  
Jianchao Wang ◽  
Kai Zhang ◽  
Yaqi Cui ◽  
...  
Keyword(s):  
Step Height ◽  
Height Reduction ◽  
Copper Cmp

A Study on the Self-Stopping CMP Process for the Planarization of the High Step Height(@step height>1.5um) Pattern

2004 ◽  
Vol 816 ◽  
Author(s):  
Kwang-Bok Kim ◽  
Hyo-Jin Lee ◽  
Ki-Hoon Jang ◽  
Joung-Duk Ko ◽  
Kyung-Hyun Kim ◽  
...  
Keyword(s):  
Chemical Mechanical Planarization ◽  
Step Height ◽  
Design Rule ◽  
Planarization Process ◽  
Series Of Experiments ◽  
Semiconductor Fabrication ◽  
Pad Conditioning ◽  
Height Step ◽  
High Degree ◽  
Polishing Pressure

AbstractCMP(Chemical Mechanical Planarization) process is widely used to reduce step height in semiconductor fabrication processes. As a design rule shrinks, a highly planar surface becomes inevitable within wafer scales. In order to get a high degree of a planarization, self-stopping characteristics of a ceria-based slurry should be studied and used in semiconductor process. In this study, threshold polishing pressure for a self-stopping characteristics was obtained by optimizing down pressure, pad conditioning, and mixing ratio of ceria abrasive and additive. A series of experiments were made to optimize the threshold polishing pressure in variable line & space patterns that consist of 0.8um step height and unit oxide film. As a result, self-stopping cmp process is twice batter than conventional silica-based process with respect to planarity and WIWNU. In addition, WIWNU and step height was dramatically decreased to less than 1000Å when applying to real fabrication devices over 2um step height.

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