Title: Surface finish improvement of an unpolished silicon wafer using micro-laser assisted machining

Authors: Hossein Mohammadi; Hüseyin Bogaç Poyraz; Deepak Ravindra; John A. Patten

Addresses: Manufacturing Research Center, Western Michigan University, Kalamazoo, MI, USA ' Manufacturing Research Center, Western Michigan University, Kalamazoo, MI, USA ' ?-LAM Technologies LLC, Battle Creek, MI, USA ' Manufacturing Research Center, Western Michigan University, Kalamazoo, MI, USA

Abstract: In this research single point diamond turning (SPDT) is coupled with the micro-laser assisted machining (µ-LAM) technique to machine an unpolished single crystal silicon (100) wafer. SPDT of silicon (Si) can be an extremely abrasive process due to the hardness of this material. Manufacturing this material without causing surface and subsurface damage is extremely challenging due to its high hardness, brittle characteristics and poor machinability. However, ductile regime machining of Si is possible due to the high pressure phase transformation (HPPT) occurring in the material caused by the high compressive and shear stresses induced by a single point diamond tooltip. The µ-LAM system is used to preferentially heat and thermally soften the workpiece material in contact with the diamond cutting tool. Different outputs such as surface roughness (Ra, Rz) and depth of cut (DoC) for different sets of experiments with and without the laser were compared and analysed.

Keywords: micro laser assisted machining; µ-LAM; single point diamond turning; SPDT; high pressure phase transformation; HPPT; ductile mode machining; brittle mode machining; infrared lasers; surface roughness; surface finish; surface quality; unpolished silicon wafers; single crystal silicon; stresses; diamond cutting tools; depth of cut.

DOI: 10.1504/IJAT.2015.073805

International Journal of Abrasive Technology, 2015 Vol.7 No.2, pp.107 - 121

Received: 07 Feb 2015
Accepted: 25 Jun 2015
Published online: 22 Dec 2015 *

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