Laser-based material processing methods and systems
First Claim
1. A method of scribing, dicing, cutting, or processing to remove material from a region of a multi-material workpiece, said method comprising:
- directing laser pulses toward at least one material of a multi-material workpiece, the laser pulses having a pulse width in a range from tens of femtoseconds to about 500 picoseconds and a pulse repetition rate of a few hundred kHz to about 10 MHz, the workpiece comprising both a pattern and a semiconductor wafer, said pattern comprising at least one of a dielectric material and a metal material;
focusing said laser pulses into laser spots having spot sizes in a range from a few microns to about 50 μ
m (1/e2); and
positioning said laser spots relative to said at least one material at a scan speed such that an overlap between adjacent focused spots for removal of material from at least a portion of the pattern is substantially greater than an overlap between adjacent focused spots for removal of material from at least a portion of the semiconductor wafer,wherein said method controls heat accumulation within one or more materials of said workpiece, while limiting accumulation of redeposited material about the region,wherein at least one laser pulse has a pulse energy of at least about 100 nJ,wherein said pattern comprises said metal material and said dielectric material, andwherein heat accumulation within said at least a portion of said pattern is sufficiently high to avoid delamination of said dielectric material from said metal material.
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Accused Products
Abstract
Various embodiments may be used for laser-based modification of target material of a workpiece while advantageously achieving improvements in processing throughput and/or quality. Embodiments of a method of processing may include focusing and directing laser pulses to a region of the workpiece at a pulse repetition rate sufficiently high so that material is efficiently removed from the region and a quantity of unwanted material within the region, proximate to the region, or both is reduced relative to a quantity obtainable at a lower repetition rate. Embodiments of an ultrashort pulse laser system may include at least one of a fiber amplifier or fiber laser. Various embodiments are suitable for at least one of dicing, cutting, scribing, and forming features on or within a semiconductor substrate. Workpiece materials may also include metals, inorganic or organic dielectrics, or any material to be micromachined with femtosecond, picosecond, and/or nanosecond pulses.
143 Citations
16 Claims
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1. A method of scribing, dicing, cutting, or processing to remove material from a region of a multi-material workpiece, said method comprising:
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directing laser pulses toward at least one material of a multi-material workpiece, the laser pulses having a pulse width in a range from tens of femtoseconds to about 500 picoseconds and a pulse repetition rate of a few hundred kHz to about 10 MHz, the workpiece comprising both a pattern and a semiconductor wafer, said pattern comprising at least one of a dielectric material and a metal material; focusing said laser pulses into laser spots having spot sizes in a range from a few microns to about 50 μ
m (1/e2); andpositioning said laser spots relative to said at least one material at a scan speed such that an overlap between adjacent focused spots for removal of material from at least a portion of the pattern is substantially greater than an overlap between adjacent focused spots for removal of material from at least a portion of the semiconductor wafer, wherein said method controls heat accumulation within one or more materials of said workpiece, while limiting accumulation of redeposited material about the region, wherein at least one laser pulse has a pulse energy of at least about 100 nJ, wherein said pattern comprises said metal material and said dielectric material, and wherein heat accumulation within said at least a portion of said pattern is sufficiently high to avoid delamination of said dielectric material from said metal material. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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Specification