Differences
This shows you the differences between two versions of the page.
| Both sides previous revisionPrevious revisionNext revision | Previous revision | ||
| front-end.md [2026/07/06 12:05] – [Processes] eric.fourboul.ext | front-end.md [2026/07/09 21:05] (current) – [Processes] eric.fourboul.ext | ||
|---|---|---|---|
| Line 1092: | Line 1092: | ||
| #### 9.1. Oxide CMP | #### 9.1. Oxide CMP | ||
| - | Oxide CMP defines | + | Oxide CMP is primarily used to flatten dielectric layers. |
| + | It is used to: | ||
| + | * flatten an interlayer dielectric (ILD); | ||
| + | * STI (Shallow Trench Isolation): after filling | ||
| + | * restoring the surface to a flat state before a new lithography or metallisation step; | ||
| + | * reducing the topography created by the previous steps. | ||
| ##### Inputs | ##### Inputs | ||
| Line 1112: | Line 1118: | ||
| #### 9.2. Tungsten CMP | #### 9.2. Tungsten CMP | ||
| + | Tungsten CMP is used to remove excess tungsten after it has filled openings. | ||
| + | It is used to: | ||
| + | * form contacts; | ||
| + | * form tungsten-filled vias; | ||
| + | * remove tungsten deposited everywhere except in the required cavities. | ||
| The most widely used approach uses ferric nitrate (Fe(NO₃)₃) or hydrogen peroxide (H₂O₂) as the oxidising agent to convert the tungsten surface to a soft tungsten oxide (WO₃) layer, which is then mechanically removed by the abrasive. | The most widely used approach uses ferric nitrate (Fe(NO₃)₃) or hydrogen peroxide (H₂O₂) as the oxidising agent to convert the tungsten surface to a soft tungsten oxide (WO₃) layer, which is then mechanically removed by the abrasive. | ||
| ##### Inputs | ##### Inputs | ||
| Line 1130: | Line 1141: | ||
| #### 9.3. Copper CMP | #### 9.3. Copper CMP | ||
| + | Copper CMP is used to form copper interconnections, | ||
| + | It is used to: | ||
| + | * remove excess copper deposited on the surface; | ||
| + | * leave copper only in the trenches and vias intended for interconnect lines; | ||
| + | * planarise after metallisation. | ||
| The most specific feature of copper CMP slurry is the use of benzotriazole (BTA) as a corrosion inhibitor. | The most specific feature of copper CMP slurry is the use of benzotriazole (BTA) as a corrosion inhibitor. | ||
| ##### Inputs | ##### Inputs | ||
| Line 1140: | Line 1156: | ||
| * Amoniac (NH3) as pH adjustor | * Amoniac (NH3) as pH adjustor | ||
| * Sodium hydroxyde (NaOH) as pH adjustor | * Sodium hydroxyde (NaOH) as pH adjustor | ||
| - | |||
| - | #### 9.1. Planarization | ||
| - | * Silicon dioxide (SiO2) | ||
| - | * Aluminium oxide (Al2O3) | ||
| - | * Cerium oxide (CeO2) | ||
| - | * Deionized water (DI Water) | ||
| - | * Hydrofluoric acid (HF) | ||
| - | * Sulfuric acid (H2SO4) | ||
| - | * Sodium hydroxide (NaOH) | ||
| - | * Potassium hydroxide (KOH) | ||
| - | * Ammonium hydroxide(NH4OH) | ||
| - | |||
| - | ##### Formula | ||
| - | |||
| - | to ad | ||
| d | d | ||
| ### Manufacturers | ### Manufacturers | ||