图 1  不同气压(2—4 Torr)下, SiH₄/H₂混合气体放电中, 放电条件为电极长度11 cm, 电极间距2 cm, 驱动频率13.56 MHz, 电压幅值50 V, 气体比例固定为SiH₄/H₂ = 1/9　(a)—(c) 周期平均电子密度; (d)—(f) SiH₃基团密度的空间分布

Fig. 1.  In the discharge of SiH₄/H₂ at different pressures (2–4 Torr), the discharge conditions are two parallel plates with a length of 11 cm and a distance of 2 cm between them, driving frequency is 13.56 MHz and a voltage amplitude of 50 V, and SiH₄/H₂ gas ratio is fixed at 1/9: (a)–(c) Period-averaged electron density; (d)–(f) spatial distribution of SiH₃ density.

图 2  沉积时间为30 s时, 不同气压下SiH₄/H₂混合气体放电的薄膜的表面形貌径向分布, 放电条件与图1一致　(a) 2 Torr, (b) 3 Torr, (c) 4 Torr

Fig. 2.  Profiles formed after deposition time of 30 s for different pressures: (a) 2 Torr; (b) 3 Torr; (c) 4 Torr. the discharge conditions are the same as in Fig. 1.

图 3  不同气压(2—4 Torr)下SiH₄/H₂混合气体放电中的离子能量分布, 放电条件与图1一致　(a) 径向中心处; (b) 电极边缘处接地电极表面

Fig. 3.  The ion energy distribution in SiH₄/H₂ mixed gas discharge at different pressures (2–4 Torr): (a) At the radial center; (b) ground the electrode surface at the edge of the electrode; the discharge conditions are the same as in Fig. 1.

图 4  SiH₄/H₂混合气体放电中, 不同气压(2—4 Torr)下沉积薄膜的氢含量、Ⅱ类反应占比以及空位占比, 放电条件与图1一致

Fig. 4.  The hydrogen content, reaction Ⅱ content and vacancy content for different pressures (2–4 Torr), the discharge conditions are the same as in Fig. 1.

图 5  SiH₄/H₂混合气体放电中, 不同SiH₄含量(10%—90%)下(a)—(c) 周期平均电子密度和(d)—(f) SiH₃基团密度的空间分布. 放电条件: 电极长度 11 cm, 电极间距2 cm, 驱动频率13.56 MHz, 电压幅值50 V, 气压2 Torr

Fig. 5.  Spatially resolved and RF period-averaged electron density (a)–(c) and SiH₃ density (d)–(f) for different SiH₄ contents (10%–90%). Discharge condition: Two parallel plates with a length of 11 cm and a distance of 2 cm between them. The frequency used in this work is 13.56 MHz and a voltage amplitude of 50 V. The discharge pressure is 2 Torr.

图 6  沉积时间为30 s时, 不同SiH₄含量下SiH₄/H₂混合气体放电的薄膜的表面形貌径向分布, 放电条件与图5一致　(a) 10%, (b) 50%, (c) 90%

Fig. 6.  Profiles formed after deposition time of 30 s for different SiH₄ contents: (a) 10%; (b) 50%; (c) 90%. The discharge conditions are the same as in Fig. 5.

图 7  不同SiH₄含量(10%—90%)下SiH₄/H₂混合气体放电中(a) 径向中心处和(b) 电极边缘处接地电极表面的离子能量分布, 放电条件与图5一致

Fig. 7.  The ion energy distribution in SiH₄/H₂ mixed gas discharge at different SiH₄ contents (from 10% to 90%): (a) At the radial center; (b) ground the electrode surface at the edge of the electrode. The discharge conditions are the same as in Fig. 5.

图 8  SiH₄/H₂混合气体放电中, 不同SiH₄含量(10%—90%)下的氢含量、Ⅱ 类反应占比以及空位占比, 放电条件与图5一致

Fig. 8.  The hydrogen content, reaction Ⅱ content and vacancy content for different SiH₄ contents (from 10% to 90%), the discharge conditions are the same as in Fig. 5.

图 9  (a) 不同相位角下双频幅值非对称电压波形; (b) 自偏压和平均离子能量变化情况^[31]

Fig. 9.  (a) Dual-frequency tailored voltage waveforms; (b) variations of self-bias voltage and mean ion energy as a function of phase^[31].

图 10  不同相位角$ \theta $下驱动极板处的(a) 离子通量和(b) 中性基团通量^[31]

Fig. 10.  (a) Ion fluxes and (b) neutral fluxes at the powered electrode for different phase angle $ \theta $, respectively^[31].

图 11  不同相位角下的刻蚀形貌 (刻蚀时间: 70 s)^[31]　(a) θ = 15°; (b) θ = 60°; (c) θ = 90°

Fig. 11.  The etching profiles at different phase angle (ething time: 70 s)^[31]: (a) θ = 15°; (b) θ = 60°; (c) θ = 90°.

图 12  不同电极间距下的刻蚀形貌^[31]　(a) 3 cm; (b) 4 cm; (c) 5 cm

Fig. 12.  Etching profiles for different gap distance^[31]: (a) 3 cm; (b) 4 cm; (c) 5 cm.

图 13  刻蚀时间为150 s时, 在接地电极处的刻蚀形貌　(a) N = 1, (b) N = 2, (c) N = 3; 在功率电极处的刻蚀形貌　(d) N = 1, (e) N = 2, (f) N = 3; 放电条件与图3相同, 灰色部分为光刻胶, 黑色部分为SiO₂, 其余颜色表示材料表面上的聚合物或钝化层^[35]

Fig. 13.  Etching profiles at the grounded electrode for (a) N = 1, (b) N = 2, (c) N = 3; and at the powered electrode for (d) N = 1, (e) N = 2, (f) N = 3 after an etching time of 150 s, the discharge conditions are the same as those in Fig. 3, grey material is the photoresist, black material is SiO₂, other colors represent polymer or passivation layers on the material surface^[35].

图 14  N = 1, 2, 3　(a) 功率电极与接地电极处的总离子通量; (b) CF₂, CF和H通量之和; (c) 中性通量与离子通量比值$ (({\varGamma}_{{\text{CF}}_{2}}+ $$ {\varGamma}_{\text{CF}}+\varGamma_{\text{H}})/{\varGamma}_{{i}, \text{Total}}) $; (d) 平均离子能量^[35]

Fig. 14.  Total ion flux (a), the sum of the CF₂, CF and H fluxes (b), the Syn value (defined as $ (({\varGamma}_{{\text{CF}}_{2}}+{\varGamma}_{\text{CF}}+\varGamma_{\text{H}})/{\varGamma}_{{i}, \text{Total}}) $ (c) , and the mean ion energy (d) at the powered and the grounded electrodes at N = 1, 2, 3^[35].

图 15  (a) 放电腔室结构和网格剖分示意图; (b) 下极板施加的裁剪电压波形

Fig. 15.  (a) The schematic of discharge chamber structure and mesh grid; (b) the schematic of the tailored bias waveform applied to the lower electrode.

图 16  密度剖面图　(a) Cl; (b) Ar⁺; (c) Cl⁺; (d) $ {\text{Cl}}_{2}^{+} $

Fig. 16.  Density profiles: (a) Cl; (b) Ar⁺; (c) Cl⁺; (d) $ {\text{Cl}}_{2}^{+} $.

图 17  离子能量分布　(a) 裁剪电压波形; (b) 射频偏压波形

Fig. 17.  Ion energy distribution: (a) The tailored bias voltage waveform; (b) radio frequency (RF) bias waveform.

图 18  (a) 裁剪电压波形和(b) 射频偏压波形下的放电中心处刻蚀形貌图(刻蚀时间: 9 s)

Fig. 18.  Etching profiles at the discharge center under the tailored bias waveform (a) and the RF bias waveform (b) (etching time: 9 s).