Quiz: Plasma-therm Icp Metal Dry Etch Tool

Explanation
Aluminum does not etch in fluorine chemistry. This is because aluminum forms a protective oxide layer on its surface when exposed to air, which prevents further reaction with fluorine. Therefore, aluminum is not affected by fluorine and does not undergo etching in fluorine chemistry.

Explanation
Plasma etching is not always anisotropic. Anisotropic etching refers to a process that removes material more quickly in one direction than in others, resulting in a specific shape or pattern. While plasma etching can be anisotropic, it can also be isotropic, which means it removes material uniformly in all directions. Therefore, the statement that plasma etching is always anisotropic is false.

Explanation
Choosing "Vent" from the Jobs/Job Start Menu in PT-MTL results in venting the load lock. This means that the air or gas inside the load lock is released, allowing for the removal of any residual gases or contaminants. Venting the load lock is a necessary step in ensuring a clean and controlled environment for the subsequent processes or operations that will take place in the chamber.

Explanation
Pressing the "Stop" button on the top menu bar in PT-MTL will immediately stop processing the wafer and give an alarm.

Explanation
Plasma is a state of matter in which atoms or molecules are ionized, meaning they have lost or gained electrons, resulting in the presence of ions. Free electrons are also present in plasma as they are detached from their parent atoms. Free radicals, on the other hand, are highly reactive species with unpaired electrons. X-rays and free neutrons are not typically present in plasma.

Explanation
If a certain material is not listed in the "Table of Available Etchers", it means that there is no specific information about which etcher should be used for that material. Therefore, the appropriate etcher for that material cannot be determined without consulting with the staff.

Explanation
The etch selectivity of polysilicon to GaN is 5.3, which means that polysilicon etches 5.3 times faster than GaN. Therefore, the material that etches faster in this given etch process is polysilicon.

Explanation
Etch selectivity refers to the ratio of the etch rate of one material to another during a process. A selectivity of 1 means that both materials etch at the same rate. If the selectivity is less than 1, it means that the material being etched is etching faster than the other material. Therefore, it is possible for etch selectivity to be less than 1.

Explanation
Downstream etching is the best type of tool to use if you want an etch process with very little or no damage due to ion bombardment. In downstream etching, the ions are generated remotely and then directed towards the substrate, minimizing the chances of ion damage. This is in contrast to RIE (Reactive Ion Etching) and ICP (Inductively Coupled Plasma) etching techniques, where ions are generated directly in the chamber and can cause damage to the substrate. Therefore, using a downstream etching tool would be the most suitable option for achieving a low-damage etch process.

Explanation
Ions can contribute to anisotropic plasma etching by removing inhibitors, which are substances that hinder the etching process. This removal allows for a more efficient and effective etching process. Additionally, ions can enhance chemical etching by reacting with the surface and promoting chemical reactions that facilitate the etching process.

Explanation
Chemical etching is included in the dry etching process for several reasons. Firstly, it helps to increase selectivity, which means it selectively removes certain materials while leaving others intact. This is important for precise etching and patterning. Secondly, chemical etching can help to decrease surface damage, ensuring that the material being etched remains in good condition. Lastly, chemical etching can create undercuts, which are recessed areas beneath the surface, allowing for better adhesion of subsequent layers. However, it does not necessarily make the process less expensive or consume ions.

Explanation
When you press "Start Job" in PT-MTL and neither "Vent After Job" nor "Process in PM, No Transfer" have been selected, the loadlock will be evacuated, and the wafer will be transferred to the process chamber. The wafer will then be processed with the selected recipe. After the process is complete, the wafer will be returned to the load lock. However, in this scenario, the load lock will remain in a vacuum state.