Interaction Between Hydrogen and Vacancy Defects in Crystalline Silicon

Abstract

Hydrogen is one of the most important impurities in silicon. It is a mobile and highly reactive species that can passivate dangling bonds at dislocations, surfaces, and interfaces, which has been widely used in the microelectronics and solar cell industry for improving device performance. Vacancy defects are elementary complexes containing dangling bonds, and the study of their interaction with hydrogen is of significant importance. In this work, the interactions of hydrogen with the vacancy‐oxygen complex (VO) and the divacancy (V2) are discussed, which are the most dominant and fundamental vacancy defects stable at room temperature. It is shown that VO and V2 can interact with both atomic and diatomic hydrogen species. This complicates the interpretation of experimental data and results in different reaction paths in differently prepared samples. Besides, some of important electronic properties, particularly electronic levels for V2Hn with n > 1, are not experimentally established.

Development of advanced hydrogenation processes for silicon solar cells via an improved understanding of the behaviour of hydrogen in silicon

“…The first is vacuum-based techniques to detect the total hydrogen concentration (including secondary ion mass spectroscopy [SIMS], 62,118 atom probe tomography [APT], 119,120 and glow discharge optical emission spectroscopy [GDOES] 121 ). The second is the detection of hydrogen complexes such as hydrogen-metal, 75,[122][123][124][125][126] hydrogendefect, [127][128][129] or hydrogen dimers, [130][131][132] typically using infrared or Raman spectroscopy, [130][131][132][133] deep level transient spectroscopy (DLTS), 98,122,123,127,134,135 or electron paramagnetic resonance (EPR). 126,129 A third is the observation of hydrogen deactivation of dopant impurities 92,99,100,136 via changes in resistivity, either locally using capacitance voltage methods 92,99 or throughout the entire silicon bulk.…”

“…Both DLTS and vibrational spectroscopy techniques have been used to observe the behaviour and properties of a range of hydrogen configurations, most notably hydrogen dimers, 133 hydrogen-vacancy complexes, [127][128][129] and hydrogen-oxygen complexes. 134,135 The limitation is that these studies typically only look at one or two specific forms of hydrogen and use tailored structures and processes to maximise the concentrations of these forms in the region of interest.…”

“…The use of the 2 H isotope greatly improves this detection limit, allowing for SIMS profiling of nearsurface hydrogen concentrations in silicon 62,118 and more recently identification of hydrogen segregation to interfaces and crystallographic defects using APT. 119,120 However, very few studies have been carried out using deuterium substitution in dielectric layers, such as are typical for hydrogen introduction to solar cells, 119 Both DLTS and vibrational spectroscopy techniques have been used to observe the behaviour and properties of a range of hydrogen configurations, most notably hydrogen dimers, 133 hydrogen-vacancy complexes, [127][128][129] and hydrogen-oxygen complexes. 134,135 The limitation is that these studies typically only look at one or two specific forms of hydrogen and use tailored structures and processes to maximise the concentrations of these forms in the region of interest.…”

Investigation of the stability and charge states of vacancy in clusters Si29 and Si38

“…For example, the stable states of the vacancy and its complexes with impurities, their formation energies were theoretically investigated in previous researches [1][2][3][4][5]. The experimental studies [6][7][8][9][10] indicated the possibility of forming the complexes of a vacancy with an impurity oxygen and hydrogen atoms in stable states, and the kinetic energies of the formation are given. This type of defects are very mobile and could be identified directly only in the silicon of 𝑝-type.…”

Hydrogen-related defects measured by infrared spectroscopy in multicrystalline silicon wafers throughout an illuminated annealing process

“…27 Diatomic forms of hydrogen, which are often electrically and optically inactive, are energetically preferable compared to monatomic forms. [28][29][30][31][32] Thus, only a fraction of hydrogen in silicon is represented by the monatomic hydrogen. Interstitial monatomic hydrogen in silicon can exist in three charge states: positive (H + ), neutral (H 0 ), and negative (H − ).…”