## 3 Results
### Experimental Results  
Experimental results are listed in Tables 1 and 2. In order to verify the proposed method, film thickness and sidewall etch angle are also measured by using a SEM. Ten samples with different lateral dimensions are tested in the experiments. Samples 1a-5a are made of Poly 1 layer and Oxide 1 layer, and Samples 1b-5b are comprised of Poly 2 layer and Oxide 1-Oxide 2 stack. Sheet resistances for Poly 1 and Poly 2 are obtained to be (12.084 \(\pm\) 0.218) \(\Omega\)/sq and (21.962 \(\pm\) 0.175) \(\Omega\)/sq, respectively. The design values of bridge widths are 10 \(\upmu\)m for sample 1 and sample 2, 15 \(\upmu\)m for sample 3 and sample 4, and 20 \(\upmu\)m for sample 5. Each sample is examined to evaluate the actual width (See Tables 1 and 2). With the knowledge of sheet resistance and bridge width, film thickness and sidewall etch angle can be determined. Measured average values of thickness for the Poly 1 layer, the Oxide 1 layer, the Poly 2 layer and the stacked layer of Oxide 1-Oxide 2 are (2.080 \(\pm\) 0.011) \(\upmu\)m, (2.142 \(\pm\) 0.012) \(\upmu\)m, (1.614 \(\pm\) 0.014) \(\upmu\)m and (2.892 \(\pm\) 0.012) \(\upmu\)m, respectively. The sidewall etch angles for the Oxide 1 layer and the stacked layer of Oxide 1-Oxide 2 are extracted as (77.51 \(\pm\) 0.61)\({}^{\circ}\) and (76.17 \(\pm\) 0.91)\({}^{\circ}\), respectively. As demonstrated in Tables 1 and 2, these results are in agreement with experimental data obtained by SEM. Figure 8: Theoretical and simulation results of the relationship between \(R_{3}\) and the geometrical parameters: (**a**) The thickness of the polysilicon layer (\(t_{1}\)); (**b**) The thickness of the PSG layer (\(t_{2}\)); (**c**) The sidewall etch angle of the PSG layer (\(\theta\)). \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Samples** & **Parameters** &
\begin{tabular}{c} **Four-Probe** \\ **Bridges** \\ \end{tabular} & **SEM** & **Error** \\ \hline \multirow{4}{*}{Sample 1a} & \(R_{S}\) & 12.26 \(\Omega\)/sq & - & - \\  & \(w\) & 10.121 \(\mu\)m & - & - \\  & \(t_{1}\) & 2.083 \(\mu\)m & 1.995 \(\mu\)m & 4.41\% \\  & \(t_{2}\) & 2.128 \(\mu\)m & 2.003 \(\mu\)m & 6.22\% \\  & \(\theta\) & 77.64\({}^{\circ}\) & 80.77\({}^{\circ}\) & 3.88\% \\ \hline \multirow{4}{*}{Sample 2a} & \(R_{S}\) & 11.97 \(\Omega\)/sq & - & - \\  & \(w\) & 10.081 \(\mu\)m & - & - \\  & \(t_{1}\) & 2.096 \(\mu\)m & 1.997 \(\mu\)m & 4.96\% \\  & \(t_{2}\) & 2.144 \(\mu\)m & 2.005 \(\mu\)m & 6.91\% \\  & \(\theta\) & 77.04\({}^{\circ}\) & 80.35\({}^{\circ}\) & 4.12\% \\ \hline \multirow{4}{*}{Sample 3a} & \(R_{S}\) & 12.01 \(\Omega\)/sq & - & - \\  & \(w\) & 15.132 \(\mu\)m & - & - \\  & \(t_{1}\) & 2.069 \(\mu\)m & 1.993 \(\mu\)m & 3.83\% \\  & \(t_{2}\) & 2.153 \(\mu\)m & 2.002 \(\mu\)m & 7.52\% \\  & \(\theta\) & 77.58\({}^{\circ}\) & 80.17\({}^{\circ}\) & 3.23\% \\ \hline \multirow{4}{*}{Sample 4a} & \(R_{S}\) & 12.33 \(\Omega\)/sq & - & - \\  & \(w\) & 15.111 \(\mu\)m & - & - \\  & \(t_{1}\) & 2.081 \(\mu\)m & 2.001 \(\mu\)m & 3.99\% \\  & \(t_{2}\) & 2.131 \(\mu\)m & 2.003 \(\mu\)m & 6.37\% \\  & \(\theta\) & 78.36\({}^{\circ}\) & 80.44\({}^{\circ}\) & 2.59\% \\ \hline \multirow{4}{*}{Sample 5a} & \(R_{S}\) & 11.85 \(\Omega\)/sq & - & - \\  & \(w\) & 20.106 \(\mu\)m & - & - \\ \cline{1-1}  & \(t_{1}\) & 2.073 \(\mu\)m & 2.001 \(\mu\)m & 3.58\% \\ \cline{1-1}  & \(t_{2}\) & 2.152 \(\mu\)m & 2.008 \(\mu\)m & 7.17\% \\ \cline{1-1}  & \(\theta\) & 76.92\({}^{\circ}\) & 79.89\({}^{\circ}\) & 3.72\% \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Experimental results of Poly 1 layer and Oxide 1 layer.