文章信息/Info

Title:

Dislocation Evolution Mechanism of GaN During Nanofabrication Based on Molecular Dynamics

文章編號:

1674-3962(2025)06-0552-09

作者:

倪自豐; 范強; 陳國美; 劉明; 陳國華; 錢善華; 卞達

1. 江南大學 機械工程學院, 江蘇 無錫 214122 2. 無錫商業職業技術學院 機電技術學院, 江蘇 無錫 214153 3. 福州大學機械工程及自動化學院，福建 福州 350108 4. 無錫格銳德半導體科技有限公司, 江蘇 無錫 214000

Author(s):

NI Zifeng;  FAN Qiang;  CHEN guomei;  LIU ming;  CHEN guohua;  QIAN shanhua;  BIAN da

1. School of Mechanical Engineering, Jiangnan University, Wuxi 214122, China 2. School of Mechanical and Electrical Engineering, Wuxi Vocational Institute of Commerce , Wuxi 214153, China et al.

關鍵詞:

GaN; 分子動力學; 壓入; 劃入; 位錯

Keywords:

GaN;  molecular dynamics;  indentation;  scratching;  dislocation

分類號:

TQ133.5+1；O73

DOI:

10.7502/j.issn.1674-3962.202311035

文獻標志碼:

A

摘要:

GaN晶體廣泛應用于新能源汽車、航空航天和軍事等領域，但硬脆性限制了其加工效率。研究精密加工中不同形狀壓頭對材料破壞損傷的影響是實現GaN高效韌性去除的關鍵。采用分子動力學對GaN晶體Ga面的壓入和劃入過程進行模擬，分析了球形壓頭以及不同朝向的Berkovich壓頭對原子堆積和滑移以及刃位錯分布和演變規律的影響。在壓入過程中，位錯主要分布于壓頭與材料接觸邊界的外圍；對于球形壓頭，Ga面上的原子滑移主要沿著<11-20>晶向族的6個方向；對于Berkovich壓頭，尖銳棱邊能有效抑制該方向原子的滑移和位錯擴展，當壓頭一尖銳棱邊朝向\[11-20\]晶向時，原子滑移以及位錯現象減少，原子滑移和堆積主要出現在垂直于壓頭3個側面的方向上。在劃入過程中，刃位錯主要經歷了滑移產生、擴展成型和破壞重組3個過程。球形壓頭劃入后產生的位錯最多，Berkovich壓頭尖角朝前劃入后產生的位錯適中，且亞表層非晶形變區域均勻，原子堆積少。

Abstract:

Gallium nitride (GaN) crystals have gained extensive usage in diverse fields such as new energy vehicles, aerospace and military applications. However, the inherent characteristics of GaN, characterized by its hardness and brittleness, adversely affect its processing efficiency. To overcome this limitation and achieve efficient and robust removal of GaN, it is paramount to investigate the influence of indenter shape on material damage during nanofabrication. Molecular dynamics simulations are employed to simulate indentation and scratching experiments on the Ga surface of GaN. The aim is to analyze the influence of employing both spherical and Berkovich indenters with different orientation to distribution and progression of atomic packing, crystal slip and dislocations throughout the machining process. It turns out that the distribution of edge dislocations is predominantly influenced by the contact interface between the indenter’s periphery and the material during the nanoindentation process. In the case of the spherical indenter, atomic slip predominantly occurs along <11-20> crystallographic direction families. For Berkovich indenter, the sharp edges are effective in suppressing slip and dislocation expansion of atoms in that direction. When the one edge of the indenter face to the [11-20] direction, atomic slip and dislocation phenomena are mitigated, and slip and atomic packing are primarily observed perpendicular to the three edges of the indenter. During the scratching process, edge dislocations undergo three main processes: initial generation, extended formation and destructive reorganization. The spherical indenter produces the most dislocations, whereas the Berkovich indenter has moderate dislocations when the sharp angle is forward, and the subsurface amorphous deformation zones are uniform, with less atomic packing.