Analysis of the electronic and chemical structure in boron and phosphorus passivated 4H-SiC/SiO2 interfaces using HRTEM and STEM-EELS

Abstract

We report a transmission electron microscopy (TEM) study of the impacts of phosphorus and boron passivation processes at 4H-SiC/SiO 2 interfaces. The chemical and electronic structures at these interfaces have been analyzed using high-resolution TEM and spatially resolved electron energy-loss spectroscopy (EELS), uncovering a range of phenomena caused by the presence of B and P within their respective boro-and phosphosilicate glass (BSG/PSG) layers. The phosphorus passivation process was observed to induce roughness at the SiC/PSG interface on the order of 100s of nm. Within the PSG layer, phosphorus was found to segregate into nanometer-scale P-rich clusters, contradicting previous reports that it is distributed uniformly throughout the PSG. Similar to N in nitric oxide annealed devices, boron was determined to accumulate in a thin layer (sub-3 nm in thickness) at the SiC/BSG interface, with a much narrower distribution than previously reported. EELS measurements indicated boron incorporates in a trigonal bonding configuration, supporting the assertion that it softens the oxide and causes significant stress reduction at the interface with 4H-SiC. These results supply further insight into the sources of mobility enhancement in PSG and BSG-gated devices that could be extended into additional improvement in the channel response of SiC MOSFETs.

Interstitial boron-doped mesoporous semiconductor oxides for ultratransparent energy storage

“…2a ), the peak at 193.8 eV in MTB-1, MZB-1, and MIB-1 corresponding to sp 2 hybridized boron matches well with those of B 2 O 3 and BO 3 (ref. 16 ). In addition, the Sn/B, Zn/B, and In/B bonding of the doped samples quantified by X-ray photoelectron spectroscopy (XPS; Fig.…”

Bias temperature instability in SiC metal oxide semiconductor devices

“…Yano et al [154] reported a combination treatment of NO and POCl 3 POA on 4H-SiC MOS devices, resulting in more stable V th and V fb than those of devices annealed either in NO or POCl 3 alone. The combination passivation of P and B on 4H-SiC/SiO 2 interfaces has also been studied, and this process may help reduce instability [178]. In addition, the combination of UV irradiation and subsequent N 2 POA can be utilized to improve the quality of the SiC/SiO 2 interface [153].…”

Boron and barium incorporation at the 4H-SiC/SiO2 interface using a laser multi-charged ion source

“…Ion deposition and implantation in Si was continued for 10 hours with 10 Hz pulse repetition rate, resulting in a dose of 5.9x10 15 , 1.8x10 15 , 9.45x10 14 , 3.5x10 14 , and 9.45x10 13 ions/cm 2 of B 1+ to B 5+ , respectively. The total number of ions bombarding the surface during the ion bombardment was ~9x10 15 /cm 2 .…”

“…X-ray photoelectron spectroscopy 3 (XPS) has shown that B reduced the size of carbon clusters at the SiC/SiO2 interface [12]. Highresolution transmission electron microscopy (TEM) and spatially-resolved electron energy-loss spectroscopy (EELS) studies showed that B accumulates in a layer <3 nm at the SiC/borosilicate glass interface and formed a trigonal bonding configuration, softening the oxide and reducing stress at the 4H-SiC interface [13]. This study also showed that P induces roughness, on a scale of hundreds of nm, at the SiC/phosphosilicate interface [13].…”

“…Highresolution transmission electron microscopy (TEM) and spatially-resolved electron energy-loss spectroscopy (EELS) studies showed that B accumulates in a layer <3 nm at the SiC/borosilicate glass interface and formed a trigonal bonding configuration, softening the oxide and reducing stress at the 4H-SiC interface [13]. This study also showed that P induces roughness, on a scale of hundreds of nm, at the SiC/phosphosilicate interface [13]. Barium has been shown to result in improvement in mobility and threshold voltage stability [9].…”