Skip to content
6CCVD Research

Wafer bow in diamond heteroepitaxy - Causes, their analytical description, and viable solutions

At a Glance

Section titled ā€œAt a Glanceā€
MetadataDetails
Publication Date2025-01-07
JournalJournal of Applied Physics
AuthorsM. Schreck, Takac Peter
InstitutionsUniversity of Augsburg
Citations2

Abstract

Section titled ā€œAbstractā€

Wafer bow is of considerable technological relevance for virtually all semiconductor materials grown by heteroepitaxy. In the case of diamond, the reported curvature values are exceptionally large for synthesis by plasma chemical vapor deposition on oxide substrates. In contrast to the usual explanation by differences in coefficients of thermal expansion (CTEs), the present analysis reveals that the CTE Ī± of the substrate combined with its thermal conductivity Ī» controls the radius of the surface on which the diamond layer will grow. The ratio Ī»/Ī± represents a figure of merit for the choice of favorable substrates facilitating maximum flatness. Calculated radii under typical process conditions fit with literature reports. Bow values exceeding these predictions significantly are attributed to the formation of intrinsic stress in diamond according to the effective climb of dislocations mechanism. Stress profiles inside of thick diamond layers after the removal of the substrate are calculated based on this mechanism taking into consideration the experimentally observed decrease in the dislocation density. They predict compressive stress in the center and tensile stress at the nucleation as well as at the growth surface in accordance with literature reports and Raman measurements. High intrinsic stress in the growing film can heavily deform the growth substrate provided that the deposition temperature is above its brittle/ductile transition. In all cases, deformation caused by extrinsic stress occurring during cooldown is =apparently of minor relevance. Two alternative strategies for the achievement of flat wafers are presented.

Tech Support

Section titled ā€œTech Supportā€

Original Source

Section titled ā€œOriginal Sourceā€

References

Section titled ā€œReferencesā€
  1. 2018 - Power Electronics Device Application of Diamond Semiconductors
  2. 2022 - Growth of single crystal diamond wafers for future device applications [Crossref]
  3. 2017 - Ion bombardment induced buried lateral growth: The key mechanism for the synthesis of single crystal diamond wafers [Crossref]
  4. 2011 - Diamond mosaic crystals for neutron instrumentation: First experimental results [Crossref]
  5. 2013 - Structural analysis of diamond mosaic crystals for neutron monochromators using synchrotron radiation [Crossref]
  6. 2014 - The first prototype diamond monochromator at the Institut Laue-Langevin [Crossref]
  7. 2020 - Growth of high-quality one-inch free-standing heteroepitaxial (001) diamond on (11-20) sapphire substrate [Crossref]
  8. 2023 - Analysis of external surface and internal lattice curvatures of freestanding heteroepitaxial diamond grown on an Ir (001)/MgO (001) substrate [Crossref]
  9. 2021 - Two-inch high-quality (001) diamond heteroepitaxial growth on sapphire [Crossref]
  10. 2022 - Growth of high-quality inch-diameter heteroepitaxial diamond layers on sapphire substrates in comparison to MgO substrates [Crossref]

Reads Similar to This

Investigation of Room Temperature Formation of the Ultraā€Hard Nanocarbons Diamond and Lonsdaleite TRANSIENT THERMAL ANALYSIS TO DETERMINE EFFECT OF CUTTING FLUIDS ON HSS AND CARBIDE CUTTING TOOLS Frequency-Tunable and Circularly Polarized Microwave Resonator for Magnetic Sensing With NV Ensembles in Diamond