Ammonium tetraborate tetrahydrate (ATT, (NH₄)₂B₄O₅(OH)₄·2H₂O) is proposed as a new, inexpensive, and direct boron source that can achieve uniform diffusion at low temperatures. It is prepared by spin coating method to improve the uniformity and decrease the diffusion temperature (T). The effects of ATT solution concentration (C_ATT) and T on the boron doped-layer are systematically investigated. An excellent uniformity is achieved, and the standard deviation coefficient (σ) of mean sheet resistance (R_sheet) is ∼ 1% at T ≥ 900 ℃ (C_ATT = 3%), which is better than the previously reported σ (>4.8%). A variety of doping profiles with mean R_sheet ranging from 14.5 to 1170 Ω/sq are obtained by controlling T and C_ATT for a diffusion time of 45 min. The mean R_sheet is 80–300 Ω/sq for T less than 850 ℃. Furthermore, the effect of surface hydrophilicity treatment on σ and R_sheet is examined by immersing the wafers in oxidation reagents before spin coating. Better uniformity of σ ∼ 0.5% is realized by improving the surface hydrophilicity through nitric acid oxidation for 1–10 min at 120 ℃. However, if the immersion time is longer than 20 min, the mean R_sheet increases due to the barrier effects of thicker oxidization layer.

四硼酸铵四水合物（ATT，(NH ₄ ) ₂ B ₄ O ₅ (OH) ₄ ·2H ₂ O）被提出作为一种新的、廉价的、直接的硼源，可以在低温下实现均匀扩散。采用旋涂法制备，提高均匀性，降低扩散温度（T）。_{系统研究了ATT}溶液浓度（CATT）和T对硼掺杂层的影响。实现了极好的均匀性，平均薄层电阻 ( R _sheet ) 的标准偏差系数 ( σ )在 ∼ 1%T  ≥ 900 ℃（C _ATT  = 3%），优于先前报道的σ（>4.8%）。通过控制T和CATT_扩散时间为 45 分钟，可以获得平均R_片从 14.5 到 1170 Ω/sq的各种掺杂分布。对于T 小于 850 ℃ ，平均R_片为 80–300 Ω/sq 。此外，通过在旋涂前将晶片浸入氧化剂中来检查表面亲水性处理对σ和R_{片的影响。}更好的σ均匀性 ∼ 0.5% 是通过在 120 ℃ 下通过硝酸氧化 1-10 分钟来提高表面亲水性实现的。然而，如果浸泡时间超过 20 分钟，由于较厚的氧化层的阻挡作用，平均R_片会增加。