Origin of room-temperature photoluminescence around C-line in electron-irradiated Si and its applicability for quantification of carbon

Abstract

We demonstrate that a broad emission band is observable at room temperature in the vicinity of the carbon-related C-line detected at cryogenic temperatures in electron-irradiated Si. Its spectral shape is different from similar shapes of the bands due to dislocations, oxygen precipitates, and thermal donors. The band is annealed out at 450 °C and its intensity ratio to the band-edge emission has a positive correlation with carbon concentration in the same manner as the C-line. We deduce that the band has a very similar origin to the C-line and discuss the possibility of carbon quantification by using the ratio as an index.

The Effect of Pull Speed and Heat Treatment on Thermal Donors in Czhocralski Silicon

“…[7] A broad emission with center energy 0.78 eV has in several studies been linked to carbon in bulk monocrystalline silicon materials. [20] However, this is not consistent with our recordings of this as a surface effect. As the low-signal strengths resulted in low Signal to noise ratio (S/N) ratio for spatial images, the unetched samples are not treated further here.…”

“…Overview of the spectral emission lines found in Cz-Si exhibiting TDs. [18][19][20] Details of each of the emission lines are shown in Table 1.…”

“…A broadband emission with similar characteristics has been attributed to carbon (C-line). [20] In the Cz-Si growing process, the upper, cooling part of the ingot can be exposed to temperatures able to induce the formation of TDs. As Cz-Si wafers exhibiting TDs are not considered as prime grade for high-efficiency solar cells without individual, further treatment, this will represent a loss for the manufacturer.…”

Review and Comments for the Development of Point Defect‐Controlled CZ‐Si Crystals and Their Application to Future Power Devices

“…Defects, such as oxygen precipitates and vacancy‐light element complexes, form due to the interaction between these impurities and point defects during device processes, such as ion implantation, so that they would degrade carrier lifetime and increase C–E leakage current and on‐voltage of IGBTs. It has recently been reported that carbon‐related complexes, such as Ci‐Cs (G‐line) and Ci‐Oi (C‐line), decrease lifetime . Therefore, reducing carbon in the crystal has been required.…”

“…It has recently been reported that carbonrelated complexes, such as Ci-Cs (G-line) and Ci-Oi (C-line), decrease lifetime. [57][58][59] Therefore, reducing carbon in the crystal has been required. In addition, because high-voltage IGBTs for infrastructure applications of a power supply require high resistivity and high lifetime materials, FZ-Si crystals with neutron transmutation doping (NTD) are used.…”