Daily Standup Notes

The Daily Scrum is a key inspect and adapt event that provides the team a formal opportunity to plan and adjust the work for the next 24 hours in order to best achieve the Sprint Goal. Answering the '3 questions' is one way that some teams may choose to achieve the outcomes of this event, however, it's not the only format that can be used. 

As for specific documents of storage, my answer would be no. I'd recommend the team finds a technique that allows the important takeaways from the Daily Scrum to be made transparent to those who need the information. Sometimes hiding it away in a document somewhere on a shared drive is not the best way to achieve this.

It seems like this question is based on some false assumptions.

The three questions you ask (and similar forms of them) are not the objective of the Daily Scrum. The Scrum Guide presents similar questions to consider as an example of a method to focus the Daily Scrum, but the structure used is set by the Development Team. The objective of the Daily Scrum is not to simply answer certain questions, but to inspect progress toward the Sprint Goal and adapt the Sprint Backlog to maximize the chances of meeting the Sprint Goal or to raise concerns early if the Sprint Goal is in jeopardy of not being met before the end of the Sprint timebox. There are many different ways to achieve these objectives and they don't all require the team to answer any questions.

As far as documentation goes, it's not required to produce any kind of document or notes. A team may choose to or not. I would suggest that the important thing to produce is either an updated Sprint Backlog. Since the meeting is timeboxed, depending on how the Sprint Backlog is maintained, it may not be feasible to update it in real time and complete the objectives, so it should be updated shortly after the event completes.

I'd also point out that the Scrum Master doesn't even need to attend the Daily Scrum. If the team has identified impediments, they should be raised to the Scrum Master. However, the team shouldn't wait for the next Daily Scrum to raise an impediment - it should be brought up as quickly as possible to start action on resolving it to minimize its impacts on the team completing their Sprint Goal. How the Scrum Master will identify and track these impediments varies - there's no one set method.

I need to understand if there is a specific document where daily standup notes are stored?

If they wish, the Development Team could make a list of impediments during their Daily Scrum. They might then bring that list to their Scrum Master's attention.

Why do you consider the existence of a "specific document" to be important?