Export CSV In Memory Instead Of Physical File

public FileContentResult DownloadCSV() {
    List < Student > studnetList = new List < Student > ();
    studnetList.Add(new Student() {
        Name = "Kuldeep",
            City = "Ahmedabad"
    });
    studnetList.Add(new Student() {
        Name = "Savan",
            City = "Ahmedabad"
    });
    StringBuilder csv = new StringBuilder();
    //Add the Header row for CSV file.
    csv.Append(GetColumnName());
    //Add new line.
    csv.Append("\r\n");
    if (studnetList != null && studnetList.Count() > 0) {
        foreach(var studnet in studnetList) {
                csv.Append(GetColumnValue(studnet));
                //Add new line.
                csv.Append("\r\n");
            }
            //Download the CSV file.
    }
    return File(new System.Text.UTF8Encoding().GetBytes(csv.ToString()), "text/csv", "Report_123.csv");
}
private StringBuilder GetColumnValue(Student student) {
    StringBuilder sb = new StringBuilder();
    sb.Append((string.IsNullOrEmpty(student.Name) ? "" : student.Name.Replace(",", ";").Replace("\n", ";")) + ',');
    sb.Append((string.IsNullOrEmpty(student.City) ? "" : student.City.Replace(",", ";").Replace("\n", ";")) + ',');
    return sb;
}

private StringBuilder GetColumnName() {
    StringBuilder sb = new StringBuilder();
    sb.Append("Name" + ",");
    sb.Append("City" + ",");
    return sb;
}
public class Student {
    public string Name {
        get;
        set;
    }
    public string City {
        get;
        set;
    }
}

<a href="@Url.Action("DownloadCSV")" >Export CSV</a>