Shallow Copy vs. Deep Copy in .NET

using System;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;
public class clsShallow
{
    public static string CompanyName = "My Company";
    public int Age;
    public string EmployeeName;
    public clsRefSalary EmpSalary;

    public clsShallow CreateShallowCopy(clsShallow inputcls)
    {
        return (clsShallow)inputcls.MemberwiseClone();
    }
}
[Serializable]
// serialize the classes in case of deep copy
public class clsDeep
{
    public static string CompanyName = "My Company";
    public int Age;
    public string EmployeeName;
    public clsRefSalary EmpSalary;
    public clsDeep CreateDeepCopy(clsDeep inputcls)
    {
        MemoryStream m = new MemoryStream();
        BinaryFormatter b = new BinaryFormatter();
        b.Serialize(m, inputcls);
        m.Position = 0;
        return (clsDeep)b.Deserialize(m);
    }
}

[Serializable]
public class clsRefSalary
{
    public clsRefSalary(int _salary)
    {
        Salary = _salary;
    }
    public int Salary;

    /// <summary>
    /// Using generics will solve some performance issues
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="item"></param>
    /// <returns></returns>
    public static T DeepCopy<T>(T item)
    {
        BinaryFormatter formatter = new BinaryFormatter();
        MemoryStream stream = new MemoryStream();
        formatter.Serialize(stream, item);
        stream.Seek(0, SeekOrigin.Begin);
        T result = (T)formatter.Deserialize(stream);
        stream.Close();
        return result;
    }

}