The p-type doping is one of the main challenges of the emerging semiconductor β-Ga2O3 technology. Phosphorus (P) implantation has been recently reported as a novel route to achieve p-type conduction on Ga2O3 at room temperature. Here, P-implanted epilayers, grown onto c-plane sapphire revealed a pseudo-metallic behavior (ρ = 1.3–0.3 Ω cm) in the 300–600 K range with a hole carrier concentration of p ⁓ 4–6 × 1018 cm−3 and hole mobility of μ = 1.2–2.1 cm2/(V·s). At sufficiently low temperature, a metal-insulator transition arises together with an increase in the positive magnetoresistance, reaching up to 200 % (9 T) large positive magneto resistance effect at 2 K. It is suggested that an Anderson delocalization model explains the room temperature conduction, and the transition to an insulator state caused by random variation of potential related to the incorporated phosphorous in Ga2O3. We believe that the lack of shallow acceptors can be mitigated by promoting Anderson disorder through the incorporation of a high level of acceptor impurities.

中文翻译：

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β-Ga2O3 中 Anderson 无序相关的 p 型电导率和金属-绝缘体转变


p 型掺杂是新兴半导体 β-Ga2O3 技术的主要挑战之一。磷 （P） 注入最近被报道为在室温下在 Ga2O3 上实现 p 型传导的新途径。在这里，生长在 c 平面蓝宝石上的 P 植入外延层在 300-600 K 范围内显示出伪金属行为 （ρ = 1.3-0.3 Ω cm），空穴载流子浓度为 p \u2012 4-6 × 1018 cm-3，空穴迁移率为 μ = 1.2-2.1 cm2/（V·s）。在足够低的温度下，金属-绝缘体转变随着正磁阻的增加而产生，在 2 K 时达到高达 200 % （9 T） 的大正磁阻效应。建议 Anderson 离域模型解释了室温传导，以及与 Ga2O3 中掺入的磷相关的电位随机变化引起的向绝缘体状态的转变。我们相信，可以通过掺入高水平的受体杂质来促进 Anderson 无序，从而缓解浅受体的缺乏。