Growth of high-quality semiconducting tellurium films for high-performance p-channel field-effect transistors with wafer-scale uniformity

Abstract

Achieving high-performance p-type semiconductors has been considered one of the most challenging tasks for three-dimensional vertically integrated nanoelectronics. Although many candidates have been presented to date, the facile and scalable realization of high-mobility p-channel field-effect transistors (FETs) is still elusive. Here, we report a high-performance p-channel tellurium (Te) FET fabricated through physical vapor deposition at room temperature. A growth route involving Te deposition by sputtering, oxidation and subsequent reduction to an elemental Te film through alumina encapsulation allows the resulting p-channel FET to exhibit a high field-effect mobility of 30.9 cm2 V−1 s−1 and an ION/OFF ratio of 5.8 × 105 with 4-inch wafer-scale integrity on a SiO2/Si substrate. Complementary metal-oxide semiconductor (CMOS) inverters using In-Ga-Zn-O and 4-nm-thick Te channels show a remarkably high gain of ~75.2 and great noise margins at small supply voltage of 3 V. We believe that this low-cost and high-performance Te layer can pave the way for future CMOS technology enabling monolithic three-dimensional integration.

High-Performance Broadband Phototransistor Based on TeOx/IGTO Heterojunctions

“…The optimal annealing temperature ( T A ) was less than 250 °C, as shown in Figure S8. When T A is ≥300 °C, the photo-electric property of the phototransistor disappeared completely due to the conversion of the hexagonal Te phase to the orthorhombic TeO 2 phase ( E G = 2.7 eV) and/or the resulting degradation of the TeO x /IGTO stack . To evaluate the performance of our TeO x /IGTO p–n junction phototransistors, we compared our obtained experimental results with datasets from previous reports, as summarized in Table .…”

“…When T A is ≥300 °C, the photo-electric property of the phototransistor disappeared completely due to the conversion of the hexagonal Te phase to the orthorhombic TeO 2 phase (E G = 2.7 eV) and/or the resulting degradation of the TeO x /IGTO stack. 48 To evaluate the performance of our TeO x /IGTO p−n junction phototransistors, we compared our obtained experimental results with datasets from previous reports, as summarized in Table 1. The performance of the TeO x / IGTO phototransistors is comparable to those of other phototransistors reported in the literature that combine an AOS and various absorption materials.…”

20‐4: Student Paper: High‐Performance p‐Channel Tellurium Thin‐Film Transistor Applications Fabricated at a Low Temperature of 150 °C

“…This distinguishable difference in the crystallinity, especially after the passivation, can be attributed to stabilization of interfacial energy [6]. It also can partially originate from reduction process during the deposition of Al2O3 passivation layer because of (1) the stronger oxidation potential of Al than Te and (2) low Gibbs formation energy of Al2O3 [6]. This alternate explanation is supported by results of X-ray photoelectron spectroscopy (XPS) as shown in Figure 3(b), where it was confirmed that the formation of Te 4+ phase located around 576 eV in the XPS spectra is considerably suppressed.…”

“…CMOS TFTs using n-channel IGZO and p-channel Te were patterned by metal shadow masks. This distinguishable difference in the crystallinity, especially after the passivation, can be attributed to stabilization of interfacial energy [6]. It also can partially originate from reduction process during the deposition of Al2O3 passivation layer because of (1) the stronger oxidation potential of Al than Te and (2) low Gibbs formation energy of Al2O3 [6].…”

“…Recently, elemental tellurium (Te) has been actively studied because of not only its low-temperature processability but also promising electrical characteristics [6]. A p-channel Te TFT can realize complementary metal oxide semiconductor (CMOS) TFTs with merits of great power efficiency and high operating speed, enabling advanced panel designs.…”