ISSN 1063-7397, Russian Microelectronics, 2017, Vol. 46, No. 3, pp. 200–204. © Pleiades Publishing, Ltd., 2017.
Original Russian Text © N.V. Shchavruk, S.V. Redkin, A.A. Trofimov, N.E. Ivanova, A.S. Skripnichenko, V.S. Kondratenko, V.V. Styran, 2017, published in Mikroelektronika, 2017,
Vol. 46, No. 3, pp. 219–223.
Partitioning Very Hard Semiconductor Sapphire Wafers
into Monolithic Integrated Circuits Using Laser
Controlled Thermal Cleavage
N. V. Shchavruk
*, S. V. Redkin
**, A. A. Trofimov
***, N. E. Ivanova
A. S. Skripnichenko
, V. S. Kondratenko
****, and V. V. Styran
Institute of Superhigh Frequency Semiconductor Electronics, ISHFSE, Russian Academy of Sciences, Moscow, Russia
Physicotechnological Institute, Moscow Technological University, Moscow, Russia
Received November 7, 2016
Abstract⎯The works on the partitioning of very hard semiconductor sapphire wafers with a diameter of
52 mm and thickness of 90 μm into monolithic integrated circuits (MICs) have been carried out using laser-
controlled thermal cleavage (LCT). The studies have been carried out and the works on cutting polycrystal-
line diamond wafers have been performed, as a result of which a method to partition the wafers into crystals,
i.e., the laser plasmochemical method of cutting, is proposed, the basic advantage of which is the absence of
the material bursting out from the cutting region and its deposition onto already formed device structures.
The very hard materials of wafers in modern semi-
conductor microelectronics are mainly represented by
sapphire and silicon carbide. When monolithic inte-
grated circuits (MICs) are formed on such wafers, the
absence of the partitioning accuracy leads to an
increase in discards and a decrease in the yield of the
known good devices from a semiconductor wafer. In
complex with the hardness and fragility of this wafer
material, this circumstance imposes a high level of
accountability on the operation of partitioning very
hard wafers into separate MICs.
Besides, partitioning a wafer into separate MICs is
performed at the final stages of the production cycle.
Such a wafer contains great labor and material expen-
diture and is costly to produce, which determines its
important place in the whole technological chain of
the semiconductor device production.
The main requirements to the operation of parti-
tioning a wafer into MICs independently of the parti-
tioning method are given below:
—high percentage of the yield of the known good
—high productivity of the equipment;
—geometric accuracy of the crystals;
—low level of cleavages at the crystal edges;
This work is aimed at partitioning very hard semi-
conductor sapphire wafers with the MICs formed on
them into separate crystals using the laser-controlled
thermal cleavage (LCT) method.
METHODS USED TO PARTITION VERY HARD
SEMICONDUCTOR WAFERS INTO SEPARATE
INTEGRATED MONOLITHIC CIRCUITS
In order to partition very hard semiconductor
wafers into separate crystals, the Institute of Superhigh
Frequency Semiconductor Electronics (ISHFSE) of
the Russian Academy of Sciences, in cooperation with
their partners, has applied various methods [1, 2].
The through partitioning of the wafer into crystals
by the method of disk cutting with the correct choice
of the cutting modes and the corresponding tools pres-
ents the possibility to obtain cuttings with the minimal
cleavages and strictly vertical crystal boundaries.
However, the method of disk cutting is economically
not beneficial for the very hard sapphire wafers, due to
the low cutting rate of 1 mm/s and determines an
increase in the wear of the cutting tool, which inevita-
bly causes an increase in the cost of the expendables .