KAUST研制出宽禁带堆叠CMOS晶体管

In the world of electronic advancements, a new technology called stacked CMOS transistors is making waves. Oxide semiconductors, known for their ability to work well in various conditions, are becoming popular candidates for realizing stacked CMOS transistors. These materials are great because they work at low temperatures, are transparent, can be made on a large scale easily, and have excellent electrical features like high carrier mobility, wide bandgap, and low gate leakage. Oxide semiconductor-based transistors are essential for their potential use in things like flat-screen displays, bendable electronic circuits, and affordable manufacturing.

在电子技术的发展世界中，一种名为叠加CMOS晶体管的新技术正在引起轰动。以氧化物半导体为基础的晶体管以其在各种条件下的良好工作能力而受到欢迎，它们在实现叠加CMOS晶体管方面显示出巨大的潜力。这些材料之所以优秀，是因为它们在低温下工作、透明、易于大规模制造，并具有出色的电气特性，如高载流子迁移率、宽禁带和低栅极泄露。氧化物半导体基晶体管对于平板显示屏、可弯曲的电子电路和经济实惠的制造至关重要。

Figure 1. (a) Scanning electron microscopy and (b) schematic illustration of 3D-stacked Ga2O3/NiO ambipolar transistors. Here, Ga2O3 and NiO are n- and p-channels respectively. (c) Cross-sectional transmission electron microscopy image of the gate region with zoom-in (d) bottom and (e) top areas of a dome-shaped fin.

图 1. (a) 扫描电子显微镜和 (b) 3D叠加Ga2O3/NiO双极型晶体管的示意图。此处，Ga2O3和NiO分别是n型和p型通道。(c) 门区域的横截面透射电子显微镜图像，以及 (d) 圆顶状鳍片的底部和 (e) 顶部区域的放大图。

One of the big steps forward in this area is the development of ambipolar oxide TFTs. These devices cleverly combine both n- and p-channels in one unit. This is a big deal because it makes creating complex electronic circuits easier, streamlines the manufacturing process, and cuts costs. A key part of this progress is making bilayer p- and n-type semiconductors. Many researchers have made important contributions in this field by creating devices like zinc-oxide and zinc tin oxide-based bilayer ambipolar TFTs. These devices work well at low voltages, have balanced mobility, and show great inverter gains. Scandium-substituted indium oxide (ScInO) is especially notable for its high inverter gains.

在这一领域的一大进步是双极型氧化物薄膜晶体管(TFT)的发展。这些设备巧妙地将n型和p型通道结合在一个单元中。这是一项重大成就，因为它简化了复杂电子电路的创建，使制造过程更为高效，并降低了成本。在这一进展中的关键部分是制造双层p型和n型半导体。许多研究人员通过创建如锌氧化物和锌锡氧化物基双层双极型TFT等设备，在这一领域做出了重要贡献。这些设备在低电压下工作效果良好，迁移率平衡，且具有很高的反相器增益。特别是掺杂钪的铟氧化物(ScInO)以其高反相器增益而著称。

Figure 2. (a) Photo of the IC chip mounted on a printed circuit board. (b) Output and gain characteristics of the inverter at VDD = ‒30 V. Input and output characteristics of the (c) NAND and (d) NOR logic at VDD = 30 V.

图 2. (a) 安装在印刷电路板上的集成电路芯片照片。(b) VDD = ‒30 V时反相器的输出和增益特性。VDD = 30 V时 (c) NAND 和 (d) NOR 逻辑的输入和输出特性。

Researchers at KAUST are focusing on gallium oxide (Ga2O3) as a promising and cost-effective choice for oxide semiconductors. Ga2O3 thin films are adaptable, can be deposited on different substrates, can be easily doped to become n-type, and have low tunneling probabilities. These features are quite advantageous. Despite the difficulties in p-doping and combining p- and n-channels on the same wafer, KAUST researchers have developed a solution by using a 3D-stacked, mixed bilayer Ga2O3/NiO ambipolar transistor (Figure 1). This new design simplifies the making process and opens new possibilities for reconfigurability and scaling.

KAUST的研究人员正将重点放在作为氧化物半导体的有前景且成本效益高的选择上——氧化镓(Ga2O3)。Ga2O3薄膜具有适应性，可以沉积在不同的基板上，易于掺杂成n型，且具有低的隧穿概率。尽管在同一晶圆上进行p型掺杂和结合p型和n型通道存在困难，但KAUST的研究人员通过使用3D叠加混合双层Ga2O3/NiO双极型晶体管开发出了解决方案。这一新设计简化了制造过程，并为电子设备的可重构性和扩展性开辟了新的可能性。

The successful combination of these ambipolar transistors starts a new chapter in CMOS logic operations. It makes creating logic inverters, NOR, and NAND gates possible (Figure 2). This achievement shows the amazing potential of stacked CMOS transistors in electronics, promising more efficient, reliable, and cost-effective solutions for electronic devices.

这些双极型晶体管的成功结合开启了CMOS逻辑运算的新篇章。它使得创建逻辑反相器、NOR门和NAND门成为可能。这一成就显示了叠加CMOS晶体管在电子设备中提高效率、可靠性和成本效益方面的巨大潜力。

Reference

参考文献

Saravanan Yuvaraja, Vishal Khandelwal, Shibin Krishna, Yi Lu, Zhiyuan Liu, Mritunjay Kumar, Xiao Tang, Glen Isaac Maciel Garcia, Dhanu Chettri, Che-Hao Liao, Xiaohang Li, “Enhancement-mode Ambipolar Thin-film Transistors and CMOS Logic Circuits using Bilayer Ga2O3/NiO Semiconductors,” ACS Applied Materials & Interfaces in press (2024)

来源：雅时化合物半导体

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