茨城大学・周立波Prof. Zhou Libo 2015/2/17 (1)
内容説明
●超精密加工■究極の加工精度■加工単位と加工方法●延性材料の加工■超高速除去加工■超高加速度除去加工(含振動加工) )硬脆材料の加工■ Siウエハの化学・機械複合加工（CMG） ■極薄Siウエハの加工IサファイアウエハのCMG加工
尚定機器(検査機器)機械コンバレータ
マイクロノータ
タイヤルゲージ電気・空気マイクロノ一精密プレス,精密シクボラ
シク研削盤、超仕上盤尤学コン精密研削整,超精密プレス
精密ラップ整（スビードワレンズ研摩機
精密グイヤモンド製盤(DUVマスクアライナ) il精密圧印,レンズ仕上研摩
機,精密グイヤモンド研飼
整,短精密研削整, 〔ステッ芯す、磁気スケ電気気コンパレータ取子コンパレコンタクト)ザ源長計HIPOS (光ファインベ),タリサーフ,タリサーフ,超精密ラップ盤、回析格子
加工機〔電子ビーム指南类
国）超高精密研削盤、超高
精密ラップ盤ポリシ盤ーサ高精度創反計(ド$重干渉コーナキュクリステップ{ Nanosurf } 〔菓子・分子・イオンビーム加工〕
菓子・分子配列加工たを重原活き更新・STM
電子線回折・イオン分析〔物質合成加工超格子〕 X線マイクロ分析
Auger分析, ESCA ( ）：半導体ウエハ処理HIPOS：全反射臨界角法STM：超トンネル効果顕微鏡Prof. Zhou Libo 2015/2/17 (3)
共有結合階の原子の電子を共有して結合します。 Diamond structure
əuə Jevomər oitiose (5) 2015/2/17 (6)

K. Eric Drexler (1955-)
Massachusetts Institute of Technology, Cambridge, MA Ph.D., Molecular Nanotechnology, September 1991 Dissertation: Molecular Machinery and Manufacturing with Applications to Computation Supervisor: Marvin Minsky ● Massachusetts Institute of Technology, Cambridge, MA S.M., Engineering, September 1979. Massachusetts Institute of Technology, Cambridge, MA S.B., Interdisciplinary Science, June 1977
.原子は電子を介して結合している.電子は原子核から見て決まった位置に存在する.電子が1つの軌道から別の軌道に移るときにエネルギ(光)を吸収した放出したりする.電子軌道間移動に伴うエネルギProf. Zhou Libo 2015/2/17 (9)
Heat process Excitation level 10-1²sec Single photo E = h v Energy Base level pico(10 1²sec) & Femto(10 15sec) Ablation process Dissociation Single photo Multi photo
●材料の除去メカニズムは,石器時代からほとんど変わっていない. Prof. Zhou Libo 2015/2/17 (11)超精密加工の要素技術環景境(振動,温度,クリーン度等）除去加工の３大要素Prof. Zhou Libo
Prof. Zhou Libo 2015/2/17 (13)
工作機械に必要な特性
位置決め精度(Positioning) ■分解能(Resolution: ~10nm/step) ■剛性( Stiffness: 1000N/μm)位置決め精度(Positioning) ■運動精度(Linearity : 0.1μm/200mm) ■多軸補間(Multi-a)位置決決め
鉄金属属アルルミ材氣料料非金金属プラスチックガラスセラミックスシリコン材料料金属属延性材料プラスチックゴムセラミックス脆性材料シリコンガラスProf. Zhou Libo 2015/2/17 (15)除去メカニズム:応力一ひずみ曲線● Example:  Steel (S45C) ■ E=210GPa, G=80GPa ■ τν=0.6GPa,τƒ=1.3GPa ■ γ =0.625%, γ =3.45% ● Specific removal energy (=Specific share stress) ■ Theoretically δ=1.0GPa ■ Practically ω=4.7GPa
● C.Solomon (German) first proposed in1931 ■ Temperature goes high together with cutting speed in the low speed region, meets its maximum and then comes down as cutting speed keeps increasing. Cutting speed ■ Undiscovered Solomon’s valley Prof. Zhou Libo 2015/2/17 (17)
Solomon’s valleyへの探検
● In 1950s, by Von Karman ■ Experiments based on theory of critical impact speed ●In 1960s, by Lockheed and Tanaka ■ Use of rifle to get higher speed ● In 1980s, By Eda ■ Use of rocket to boost up the cutting speed
Prof. Zhou Libo
2015/2/17

MPa rength Prof. Zhou Libo 2015/2/17 (19)延性材料の動的特性Prof. Zhou Libo 100 % 80 60
E p p density of material ρ : σ : stress ε ： plastic strain • Rich in plasticity • Relatively low v p
Prof. Zhou Libo 2015/2/17 (21) Experimental set-up d o 1 H '
(23) (24)
Prof. Zhou Libo 2015/2/17 (25)
Prof. Zhou Libo 2015/2/17 (27)
Interatomic spacing(0.235nm)
Inter-atomic force given by potential f (r) = dφ(r) = 2αD[exp{− 2α(r dr Interaction between particle i and j Fx . x i - X i f (r) rij Yi - Yi f(r) rij Force acting on the particle i Fx, =   Fx, dt ²
Simulation parameters
Abrasive grain Workpiece Model Inter-atomic potential Integral calculation Initial temperature  T Diameter of abrasive  D Grinding speed  V Work speed  v Depth of cut  d Grinding distance Rigid diamond  C (111) Al (111)  (fcc metal)  (plasticity propagation speedニュ＝ 200~300m/s) 2-D Plane strain Morse (Al-Al, Al-C) Leap frog ∂σ sp 300 K   10.4 nm 50 - 2000m/s 0 2 nm (8 atom layers) 67 nm Prof. Zhou Libo
2015/2/17
(32)
2015/2/17 (33) raveling distance at V=300m/s 0nm 0. 5nm 1.0nm 1.5nm 2.0nm Prof. Zhou Libo
Prof. Zhou Libo 2015/2/17 (35) Traveling Distance of Atom
Prof. Zhou Libo 2015/2/17 (37)
得られた成果
“High speed”は再定義する必要がある:塑性伝播速度と材料に依存.塑性伝播速度を超えて切削すると,延性材料の弾性域が大きくなり,脆性的な挙動を示す.その結果塑性変形が小さくなり,仕上げ面粗さを含む加工品位の向上ができる.分子動力学シミュレーションにより,上述の現象を理論的に証明した.
PRECISION ENGINEERING Material removal mechanism beyond plastic wave propagation rate Libo Zhou'. Jun Shimizu, Akihito Muroya, Hiroshi Eda vering, Darabi University, Nokmarkawa 4-12-1, 316-5511 Huschi-shi ted 28 March 2003 2001 ; received in projed form 4 March 2002 ; access Ustract ied in thas report satenals are elastically thro Nanotechnology and nanostructured materials: Trends in carbon nanotubes ) Material removal mechanism beyond plastic wave propagation rate Back to top Measurement - Top cited articles from 2003 - 2004 Fuzzy approach to the theory of measurement inexactness 2) Measurement models: Application of intelligent methods 3) Unsteady flow generator for gases using an isothermal chamber Back to top Applied Ergonomics - Top cited articles from 2003-2004 The material removal takes place at three different regime [1.2]: elastic regime, plastic/ductile ending on the minimum controllable removal unit. From are respectively correspondent to the elasts. ion, plastic flow, and fracture initiation. For most of (fracture) strength on is approximately equal to the vield e brittle materials, before they are shared off. The energy E κ necessary for material removal is simplified as elastic strain energy and the plastic strain (1) Xy the ultimate deformation, and x, is the elastic defor- mation. The plastic energy (2nd and 3rd term) stands out intly in the Ea. (1). and contributes more than 2015/2/17 (39) Prof. Zhou Libo
(a) Brittle material廊性材料(b) Ductile material延性材料
Prof. Zhou Libo 2015/2/17 (41)
研究目的と方法
● Objective
to generate a perfect (defect free) surface by fixed abrasive process ● Methodology by introducing chemical reaction into grinding process Expected chemical reaction Si Abrasive (CeO₂,SiO₂)   ⇒ Additives (Na,CO,)  ⇒   Si Coolant (KOH)  ⇒  Si Prof. Zhou Libo (42)
CEROX 1650   Av. Size: 2±1μm,  purity: 70% Prof. Zhou Libo 2015/2/17 (43) Lattice fringe with spacing 0.58 nm Average particle size : 1.5μm
CeO₂ abrasives

Prof. Zhou Libo 2015/2/17 (45)
Polished year 2000 year 2002 Commercialized Ra=0.81nm, Ry=5.8nm Prof. Zhou Libo 2015/2/17 (47) Ibaraki University
(a) CMP (b) CMG Prof. Zhou Libo 2015/2/17 (51)
Prof. Zhou Libo 2015/2/17 (53) CMG wheel composition analysis
Prof. Zhou Libo 2015/2/17 (55) Grinding waste composition analysis
2(CeO₂)+2e- ↔ 2(CeO₂)- ↔ Ce₂O₃ + ₂ O₂ Si + O 2  → (SiO) 2 +  + 2e-  → SiO 2 J (SiO)²† + 2(CeO²)¯ → Ce²O³ · SiO² (Amorphous) Prof. Zhou Libo 2015/2/17 (57)
P−8
Process simplification

Prof. Zhou Libo

● Back-grinding: extremely thin wafer ■ Power device (IGBT)  (Automotive, etc.) ■ Mobile device (Electronics) ● Replacement of free slurry Bare wafer processing (Semiconductor ■ material) ■ Planarization (IC manufacturer) ) Other electronic and photonic substrate Crystallized glass (Electronics and optics) Compound semiconductor (LT, Sapphire) Prof. Zhou Libo
Extremely-thin ground Si wafer Surface roughness of CMG wafer Prof. Zhou Libo 2015/2/17 (61) Thank you for your attention Please contact lbzhou@mx.ibaraki.ac.jp for question, suggestion or comment. 2015/2/17 (62)