Diamond Nucleation and Seeding Techniques: Two Complementary Strategies for the Growth of Ultra-thin Diamond Films

Abstract

The controlled growth of ultra-thin diamond layers on a diversity of substrates is a major challenge for many technological applications (heat spreaders, electromechanical systems, etc.). This explains the huge effort produced during the last two decades to master the early stages of diamond formation. Two main pathways have been investigated in the literature. The nucleation pathway aims to produce diamond nuclei, i.e., the smallest thermodynamically stable diamond islands, at the substrate surface. This is mainly performed by in situ treatments preceding diamond chemical vapor deposition (CVD) growth, such as bias enhanced nucleation (BEN). The second approach consists of skipping the nucleation stage by covering, ex situ, the substrate with diamond nanoparticles, which act as seeds for diamond CVD growth. The present chapter is a review of these pathways. Their respective benefits and drawbacks are discussed. Finally, these two approaches appear very complementary. Seeding allows the growth of ultra-thin diamond layers on large non-conductive substrates with micrometric patterns. On the other hand, the BEN in situ nucleation treatment remains the favored technique to achieve well-adherent diamond films and diamond heteroepitaxy.

Nanodiamonds: From Synthesis and Purification to Deposition Techniques, Hybrids Fabrication and Applications

“…Indeed, seeding with NDs represents an alternative to in situ nucleation methods like Bias Enhanced Nucleation (BEN) [20]. Sequential XPS analysis confirmed the stability of detonation NDs (5 nm) under CVD conditions [94].…”

“…Contrary to BEN, 3D substrates like silicon tips [102,103] or silica optical fibers [104] can be homogeneously coated [105]. The main challenge is the improvement of diamond films adhesion [20,93]. An optimized seeding would combine a high density of seeds (up to 10 11 /cm 2 ) with a seed size as small as possible.…”

“…Under specific conditions, homoepitaxial diamond films can be grown by CVD onto HPHT substrates. For growth of diamond films on heterosubstrates (Si, 3C-SiC, Ir,…), nucleation methods like bias enhanced nucleation (BEN) or seeding protocols were developed [20]. In CVD diamond, the level of impurities can be accurately controlled.…”

Recent Progress of Nanodiamond Film in Controllable Fabrication and Field Emission Properties

“…Before synthesizing the ND films by CVD, a diamond seeding process is a critical step to essentially enhance the nucleation quality and smoothness of ND film in non-carbide forming substrates [ 42 , 43 , 44 ]. Many seeding procedures are employed for the ND film growth, including mechanical abrasion method with a diamond grit, spin-off coating method on the substrate with a diamond-containing particles, printing method of seeds by a stamp brought in contact with the substrate, ultrasonic treatment method in a suspension of diamond powder, and bias-enhanced nucleation (BEN) deposition of diamond on a substrate [ 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 ]. The quality of ND film is directly dependent on the seeding parameter, such as the density and size distribution of ND particles.…”

Nanoparticle Adhesion and Mobility in Thin Layers: Nanodiamonds As a Model

“…Stable fluorescence properties could be also introduced through nitrogen vacancy centers created by irradiation and annealing. − A large number of in vitro and in vivo studies have confirmed that ND have very low cytotoxicity on numerous cell lines including osteoblasts and neuroblasts, glial and marrow, liver, kidney, intestine and lung cells. − Further than simple biocompatibility due to chemical inertness, Thalhammer et al reported that an ND monolayer coating even promotes the formation of a functional neuronal network. , Finally, diamond nanoparticles exhibit excellent tribological properties. ,− All the properties mentioned above make ND highly desirable for a wide range of applications in various fields, either dispersed in colloids or deposited on a surface. The latter case includes seeding prior to film growth by chemical vapor deposition (CVD), − protective coatings against corrosion, , tissue scaffold engineering, , platforms for protein immobilization on biosensors, sensitive coatings for surface acoustic wave sensors and attachment to probe for nitrogen-vacancy center mapping …”